Again, in the end of 187 1, Agassiz left for South America, on board the war-ship Hassler, Count Pour- 576 NATURE \April 24, 1879 tales, in this well-known expedition, had charge of the deep-sea researches, while Dr. Steindachner with Agassiz, was responsible for the other zoological collections. The results of this expedition are well known to naturalists. The leisurely cruise along the coast of Patagonia and Chili gave Agassiz an opportunity of studying the glacial phenomena of South America. His stay in San Francisco and Sacramento gave an impulse of the greatest import- ance to education and science in these towns, and in the latter led to the creation of a . Natural History Society, which was named after him, the Agassiz Institute. The history of the Penikese School of Natural History must be so fresh in the memory of our readers that we need not here repeat the details. The success of the school, modelled somewhat after that of Dohrn, at Naples, exceeded all expectation, the accommodation being quite inadequate for the number of students who appeared. At the end of the first summer his pupils bade him a long good-bye in the hope of meeting their much- loved master next year. But the additional burden seems to have been too great for the strength of the never-resting devotee of science. After scarcely eight days' illness, he died at Cambridge, December 14, 1873, in his sixty-third year, in the height of his fame. He has been justly named by his fellow-citizens of the States the " Humboldt of America." Ever amiable and open in intercourse, stimulating and instructive, clear and concise in exposition, was Agassiz ; and his numerous pupils, of whom several have developed into important workers in science, as Alex. Agassiz, Stimpson, Putnam, Shaler, Wilder, Morse, &c., 'clung to him with truly child-like love and respect. The news of his unexpectedly sudden death shocked the whole population deeply, for America had lost in him one of her citizens of whom she had the best right to be proud. Besides Dr. Steindachner' s paper, we would refer the reader who desires further details to a paper in the Revue des Deux Mondes for July and August, 1875. WATERTON'S LIFE AND TRAVELS Wanderings in South America, the North-West of the United States, and the Antilles, in the Years 1812, 1816, 1820, arid 1824. With Original Instructions for the Perfect Preservation of Birds, &c., for Cabinets of Natural History. By Charles Waterton. New Edition. Edited, with Biographical Introduction and Explana- tory Index, by the Rev. J. G. Wood. With 100 Illus- trations. (London : Macmillan and Co., 1879.) THE reading world will feel grateful to both author and publisher for this handsome edition of one of our classical books of travel and natural history ; while those who are already familiar with the work will read with interest and pleasure the excellent biographical notice of Waterton here given. We have first a sketch of his school and college life, when his taste for natural history got him into many scrapes ; but we learn that the Jesuit fathers at Stonyhurst wisely utilised his irrepressible love of animals by making him rat-catcher and general vermin-killer to the estabhshment. We next find him travelling on the Continent, where he had a narrow escape of dying of the plague at Malaga. He visited Gibraltar, and saw a whole colony of the well-known apes which were then far more abundant than now. He speculates on the "tremendous convulsion of nature" which had opened the channel of the Straits, observing that — " if apes had been on Gibraltar when the sudden shock oc- curred, these unlucky mimickers of man would have seen their late intercourse with Africa quite at an end" — a passage which recalls to us those extreme catastrophist doctrines in geology which are now happily extinct. When his wanderings in South America were at an end he settled down in his ancestral Yorkshire home, Walton Hall, devoting himself to the management of his estate and the study of nature, and living a life of the most Spartan simplicity. His single room had neither bed nor carpet. He always lay on the bare boards with a blanket wrapped round him, and with an oaken block by way of pillow. He went to bed at eight, and was up, dressed and clean shaven every morning at four, having himself lit a fire and boiled water to shave with. His devotions and reading occupied him till six ; his bailiff's report, writing and business till eight, his breakfast hour ; so that he had done a fair day's work before most people are out of bed. His room was at the very top of the house ; he never touched fermented liquors, and took very little meat. His great delight was in studying the habits of birds and other wild animals ; and he devoted his park of over 250 acres to this purpose. He had moats, and ponds, and swamps, woods and trees of all kinds ; and he spent 10,000/. in suiTOunding the whole with a wall nowhere less than eight feet high, in order to keep out poachers and animal intmders. In this domain no gun was ever fired or anything done to disturb the feathered inhabi- tants. The very year after the wall was finished the herons came and established themselves in the park, where they had never bred before ; and, as Mr. Wood re- marks, it is strange that they should have known that the wall, which they themselves could so easily pass, would be any protection to them. He constructed a yew fort- ress for pheasants, built a cat-proof tower for starlings, and a lofty dovecot to secure his pigeons from poachers. Owls and titmice and many other birds had special haunts constructed for them, while rats and other bird-enemies were carefully trapped or poisoned. Waterton was one of the kindest and most humane of men. He studied the comforts of his horses, his dogs, and even of his pigs, as if they had been human beings. He had his gates specially constructed so that his horses and cows could lean over them and converse together, without inconvenience to themselves or injury to the gates. When he took possession of a deserted country house in Demerara, tenanted by frogs and snakes, owls and vam- pires, he tells us in his quaint language,—" The frogs, and here and there a snake, received that attention which the weak in this world generally experience from the strong, and which the law commonly denominates an ejectment. But here neither the frogs nor serpents were ill-treated ; they sallied forth, without buffet or rebuke, to choose their place of residence ; the world was all before them. The owls went away of their own accord, pre- ferring to retire to a hollow tree rather than to associate with their new landlord. The bats and vampires stayed with me, and went in and out as usual." Even when, going down the St. Lawrence, he caught, crawhng on his neck, the only bug he saw in North America, he " thought of my uncle Toby and the fly ; " and so, instead of killing it, he "quietly chucked it among some baggage that was April 24, 1879] NATURE 577 close by, and recommended it to get ashore by the first opportunity." Any -vvild animals that he does not actually want for specimens he treats in the same way, and it is therefore not surprising that he looks favourably on the Indian and 1 his mode of life. Ignorant travellers and colonists call the f Indians a lazy race ; "but," he remarks, "man in general will not be active without an object. When an Indian has got plenty to eat, what need has he to work ? He has no idea of making pleasure-grounds. Money is of no use to him as there are no markets for him to go to, nor mil- liners' shops for his wife and daughters. He has no taxes to pay, no highways to keep up, no poor to maintain, no army nor navy to supply. He lies in his hammock both night and day (for he has no chair nor bed, neither does he want them), and in it he forms his bow, and makes his arrows, and repairs his fishing-tackle. But when his provisions are gone he rouses himself, and scours the forest in quest of food. He plunges into the river after the deer and tapir, or passes through swamps and quagmires, and never fails to obtain food. With us the poor or needy man has to work every day and all day long for a maintenance, but should this man ac- quire a fortune he usually changes his habits." Water- ton then amusingly sketches for us the life of an idle man for a single day, and concludes : — " Now, could the Indian in his turn see this, he would call the white men a lazy, indolent set. Perhaps, then, upon due reflection, you would draw this conclusion : that men will always be indolent when there is no object to rouse them." Not even Gilbert White was a closer or more accurate observer of the habits of animals than was Waterton, and had he recorded all his observations during the forty years he lived at Walton Hall we should have had a work in no way inferior to White's " Selborne." There is one curious observation of his which throws some light on the origin of one of the superstitions of natural history, but which seems to have been entirely overlooked. The name Caprimulgvs, or " goat-sucker," has its equivalent in many European languages ; and the belief that this bird sucked goats or cows has been prevalent since the time of Aristotle. The only foundation for this wide- spread belief, suggested in any ornithological book to which I have access, is, that the goat-sucker is often found near sheep-folds and cattle-pens on account of the abun- dance of insects in such places. Pliny however says that they enter the folds and fly to the udders of the goats in order to suck the milk. This is a much more definite statement, and, strange to say, Waterton supports the fact thus stated by his own observ^ation, and at the same time shows how the erroneous inference arose from this fact. At p. 233 of this volume we find the follow- ing: — "I am fully persuaded that these innocent little birds never suck the herds ; for when they approach them, and jump up at their udders, it is to catch the flies and insects there. In another passage at p. 198 this is certainly the case. He says (according to his custom addressing his reader as if speaking to him) : — " When the moon shines bright you may have a fair opportunity of examining the goat-sucker. You will see it close by the cows, goats, and sheep, jumping up every now and then under their bellies. Approach a little nearer,— see how the nocturnal flies are tormenting the herd, and with what dexterity he springs up and catches them, as fast as they alight on the belly, legs, and udder of the animals. Obsen'e how quiet they stand, and how sensible they seem of his good offices, for they neither strike him, nor hit him with their tail, nor tread on hina, nor try to drive him away as an uncivil intruder,' There can be no doubt that these are Waterton's own observations at home, though expressed rather generally ; but the other passage, at all events, written in the first person, is far too definite a statement to be doubted, coming from such an observer; and it is curious that no modern writer on the subject appears to have referred to it. As a capturer of snakes W^aterton was pre-eminent, his fight with the great boa constrictor, and his capture single- handed of a smaller one, which he allowed to coil round his body while he held its neck in his two hands, are well- known incidents in his " Wanderings ; " but Mr. Wood tells us how he coolly manipulated live rattlesnakes in the presence of a number of friends at Leeds, transferring them from one box to another with his bare hands. His secret was, simply, that if a snake is not frightened by noise or sudden movements, its natural sluggishness pre- vents it from resenting cautious handling. We quite agree with the editor that few books have ever been written so thoroughly truthful and accurate, and so entirely free from exaggeration as those of Water- ton ; yet his veracity was often doubted by his reviewers, and he was classed among travellers of the Munchausen type. This however he little cared for, but he did not like to be called eccentric. He thought himself the most ordinary of human beings, though he climbed trees bare- foot and never in his life wore a black coat. " Yet," as Mr. Wood well says of him, " had he not been eccentric he would not have been the Charles W^aterton so long known and loved. ... It was eccentric to come into a large estate as a young man, and to have lived to extreme old age without having wasted an hour or a shilling. It was eccentric to give bountifully and never allow his name to appear in a subscription list. It was eccentric to be satu- rated with the love of nature. It might be eccentric never to give dinner-parties, preferring to keep an always open house for his friends ; but it was a very agreeable kind of eccentricity. It was eccentric to be ever childhke but never childish. We might multiply instances of his eccentricity to any extent, and may safely say that the world would be much better than it is if such eccentricity were more common.' ' So far we have had only praise for this book, and 578 NATURE {April 2 Af, 1879 though we have said nothing yet about the illustrations, they are also worthy of commendation as really illus- trating the matter in hand, and being for the most part of excellent quality. But now we have the less pleasant duty of finding fault. Waterton had a strong prejudice against the use of scientific names. He tells us that the Salempenta is excellent eating ; that you hear the voice of the Hannaquoi at early dawn ; while such words as Conanacouchi, Labarri, and Karabimiti are continually used without any explanation of their meaning. In pur- suance of his duty as editor Mr. The name of the "coral-snake" is given as Tortrix scytale, whereas the species belongs to a quite distinct family, being either an Elaps or a Plioceriisj while the deadly "labarri" snake is named Elaps letnniscatus, though, from the description Waterton gives, it is almost certainly a Craspedocephalus. The red grosbeak, which Waterton mentions as a rarity he was long in search for and gives a recognisable description of, is called Cat- dinalis virginianus, a bird not found in Demerara ; whereas it is almost certainly the Pitylus erythromelas. The little tiger-bird is said to be a Tigrisoma or tiger- bittern ; but Waterton's^description shows it to be Capita cayanensts, a fruit-eating bird of a totally distinct family. The " yawaraciris " are said to be manakins of the genus Pipra ; but. the description in the text clearly points to the well-known " blue creepers" of the genus Coereba. The jay of Guiana described by Waterton, and which Mr. Wood could not determine, is the Cyanocorax cay anus, while the " grand gobe-mouche," which is omitted from the index, is easily recognisable as the Querula 7-ubri- collis. Of the plant identifications I am not prepared to speak, except to remark that the cultivated pineapple is certainly not a species of Pitcairnea. It is to be hoped that this delightful work will come to a second edition, and admit of these blemishes being removed. It would also be a great convenience if re- ferences were added to the explanatory index, to avoid the trouble of first going to the index proper and then back to the body of the work. These, however, are matters which, though important to the student who keeps the book for reference, will not much affect the enjoyment of the general reader ; and I can therefore cordially recommend all who have not made the acquaint- ance of the "Wanderer" to do so in the pages of the present volume. A. R. W. OUR BOOK SHELF Ueber ehemalige Strandlinien in anstehendem Pels in Nor- wegen. Dr. R. Lehmann. (Halle, 1879.) Probably no feature of Scandinavian geology has been more frequently discussed than the remarkable lines of terrace which have been traced along the slopes of the coast, even up into the far northern fjords. Certainly no stranger, even if ignorant of geology, can visit these regions without being impressed by the freshness and persistence of these "parallel roads," which wind in and out among the intricate navigation of strait and sound, islet and archipelago. From the time of Celsius down- wards a continually increasing literature has been devoted to this subject, and now Dr. Lehmann, of the Realschule, in Halle, adds another essay to the pile. He discusses at length and rejects the theories of erosion by glaciers and by floating ice, and adopts that of breaker-action. But probably no exclusive theory is correct. Unquestionably Norway has been overridden by land-ice, scarped and notched by coast-ice, as well as cut into by tides and breakers. That the terraces mark lines of former sea- level seems so self-evident that it hardly deserves more than a simple mention of the fact. But when these lines were cut out of the rock and the land was a hundred feet or more lower than it is now, the coasts were doubtless cumbered with ice, and while the breakers were grinding out a platform from the solid rock, their work was probably expedited by drifting masses of floe-ice. Dr. Lehmann' s pamphlet is useful for the collected references it contains to recent literature on the subject. But it is needlessly voluminous. Die Lust an der Musik. Erklart von H. Berg. B. Behr's Buchhandlung. (Berlin, 1879.) This is a little pamphlet which we have perused with no small amount of disappointment. After a short chapter treating of the origin of music, in which the author merely recapitulates the theory expounded by Darwin long ago, we come to Chapter II., on the development of music, in which the author states very little that has not before been stated by Darwin, and particularly by Helm- holtz, in his " Lehre von den Tonempfindungen." The principal chapter, viz., that on the effects of music, in which we expected to find the explanation promised in the title of the pamphlet, or at least the expression of some new ideas on the subject, occupies but four small April 2/^, 1S79] NATURE 579 pages, and contains merely a iev/ illustrations of the capacity inherent in music of modulating the pleasant sensation it produces in the mind of man in a number of various ways. An appendix treats of the pleasure man derives from the aspect of colours, certain forms, and the beauty of the human body. LETTERS TO THE EDITOR {The Editor does not hold h imself responsible for opinions expressed by his correspondents. Neither can he undertake to return, or to correspond with the writers of, rejected manuscripts. No notice is taken of anonymous communications. [The Editor urgently requests correspondents to keep their letters as short as possible. The pressure on his space is so great that it is impossible othenvise to ensure the appearance even of com- munications containing interesting and noz^el facts."] On the Spectrum of Brorsen's Comet The observations of Prof. Young on the present appearance of the spectrum of Brorsen's comet are of great interest, from the circumstance to which he refers in his letter in Nature, vol. xix. p, 559, namely, that in 1868 I found the positions of the three bright bands of this comet not to agree with those of other comets which I showed to be coincident with the bright bands in the spectrum of flames containing carbon. The care I bestowed upon the determination of the apparently anomalous character of the spectrum of Brorsen's comet in 1868 gives me great confidence in its approximate accuracy. I wish now to call attention to the fact that a spectrum apparently essentially similar to the peculiar one exhibited by Brorsen's comet in 1868, was observed at Dunecht by Lord Lindsay in the case of Comet C 1877 (Borelly's). It is remarl<able that another comet, Comet B (Winnecke's) 1877, observed by Lord Lindsay on the same evening (May 6) presented the ordinary cometary spectrum. Lord Lindsay's diagram in the Monthly Notices R.A.S. (vol. xxxvii. p. 431) of these two spectra agrees as nearly as can be expected in such observations with my diagram in the Phil. Trans., i868 (PI. xxxiii.), contrasting the spectrum of Comet B, 1868, with that of Brorsen's comet. It may be accepted, therefore, as beyond doubt that the un- usual form of spectrum of Brorsen's comet in 1868 is occasion- ally presented by comets. The great interest of Prof. Young's observation lies in the information which it gives us that the same comet may present on one occasion one spectrum, and on another the other spectrum, I regret that the special arrangement of my telescope for pho- tographic work does not permit me to observe the spectrum of Brorsen's comet at its present appearance. Upper Tulse Hill William Huggins The Migration of Birds In Nature, vol. xix. p. 433, there is a notice of my paper " Ueber das Wandern der Vogel," to which I have somewhat to reply. However agreeable it is to me that my views should be com- municated to your readers, and however little I object to their being submitted to rigorous criticism, I must still also desire that this criticism be fair. I believe it is due to differences of national customs that your reviewer has not quite satisfied this desire. We make, perhaps, in Germany a sharper distinction between a scientific treatise and A popular \,oxV. than in England. Of the latter we do not re- quire that it bring forth what is new, but only that it should give what it has to give in a clear and easily intelligible manner. Nor do we require completeness of such a work, or even a criticism of the scientific works on which it is based ; indeed, it is gene- rally left to the author how far to cite his sources of information »nd how far not. In the scientific treatise it is quite otherwise ; here only that is of value which is new ; the theme must be treated exhaustively ; the sources must always be named and dealt with critically, &c. Now my publication is a lecture, which was delivered before a company of educated ladies and gentlemen, and so before mere laics, Md a year and a half afterwards was printed in Virchow and Holtzendorff's Collection of Popular Lectures. It thus belongs unquestionably to the categorv of popular writings. For this reason your severe critic had no occasion to point out that in my lecture there is much that had been long known, that sources are named but rarely, and that no scientific criticism is exercised. That is quite a matter of course in a popular work, at least in Germany. Mr. Newton would have had much better right to feel surprised that even any new ideas were contained in it. My original aim in this lecture was merely to make my hearers acquainted with the new facts and views on the migration of birds, as they have been established by Wallace, Middendorff, and especially by Palmen. As I followed the new facts theo- retically to their consequences, there arose perhaps some new ideas, which I should be glad to find verified in the future. It is further a matter of course that, notwithstanding the popular form of my work, I stand by all that I have said ; but I must protest against being made responsible for what I have not said! Thus, e.g., I have nowhere said that I hold Palmen's routes of flight for "absolute truths." I am rather quite of Mr. Newton's opinion, that these routes are merely inferred, not directly ob- served, and therefore that they are to a certain extent "conjec- tural." In this sense, however, the routes of birds must ever remain comparatively "conjectural," unless one were to follow the birds in a balloon. But while "conjectural," Palmen's routes are yet inferred by a purely scientific method, and I doubt not that most of them will in the main be confirmed by further observations. Precisely in the application of this method lies Palmen's great merit, and it is only to be hoped that ornitho- logists w ill follow further in his footsteps, and correct his mis- takes by accumulation of new facts. That Palmen's routes con- tain some errors I do not doubt ; I should rather wonder if it were not so. Little, however, comes of this with reference to the questions which are treated with special fulness in my lecture, the origina- tion of the instinct of migration, and the powers by which the bird reaches its distant goal. I have, further, nowhere said that birds fly over the sea at a height of 20, coo feet, but have merely cited the fact that birds have been seen at such height ; with reference, of course, to ex- planation of their flight over the sea, I believe that birds, in flight over the sea, do not close their eyes, but exercise their keen eyesight as far as possible. Therew ith, however, it is not said (as Mr. Newton imputes to me) that in all flights over the sea they always keep the land in sight. I desist from adducing further misunderstandings by Mr. Newton, and come to what / have actually said and am minded to maintain. In agreement with Palmen, I have expressed the opinion, that migratory birds have no special sixth sense, as Middendorff has assumed, but that they find their way only with the help of their cn-dittary five senses. Mr. New ton seems to be of a different opinion. He does not say, indeed, whether he agrees with Middendorff, but he brings forward observations which appear incapable of harmony with my view. First, there appear in New Zealand two species of cuckoo ( Chrysococcyx lucidus and Eudynamis taitensis) which regularly fly some 1,000 miles' distance over the ocean. I believe with Mr. Newton that the birds cannot fly so high as to see at once New Zealand and the Norfolk or Kermadec Islands, though on the former is a hill of i,oco feet. Likewise I will accept the case of Charadrius pluvialis as a regular guest of the Bermuda Islatids, and a doubtful Charadrius species as regular guest of the Sandwich Islands. All these observations are, indeed, still very imperfect, inasmuch as it is not known whence the birds come nor whither they go ; but so much seems certain, that they do regularly fly over large stretches of ocean in w hich are almost no islands or rocks, and which are so great that they must of course also fly by night. What then? Are we therefore compelled to make the assumption, with Middendorff, of a sixth sense, which informs the bird which direction is north ? Is there no simpler explana- tion of the fact ? Obviously, we should only be warranted in accepting such a purely hypothetical sense, if it were clearly proved, that we could never get to understand the facts without it. The question had already occupied me, before I knew of Mr. Newton's examples. I omitted it in my lecture, because it seemed to lead me further into the region of hypotheses than I considered I could answer for before my audience. 58o NATURE [April 24, 1 8"' I do not believe that we are necessitated by the far sea flight of birds, to assume a sixth sense. Is it not conceivable that birds are capable of keeping exactly the same direction of flight for many hours together, and so to fly somewhat like a shot ball or a steamship with rudder bound fast ? From the physiological side, it might of course be objected that a very slight difference in the strength of the right and left wing-beats must cause a de- flection from the original course, just as in the case of rowing without a steersman, a constant control by sight is necessary, if the right direction is not to be lost. To this might be replied, however, that birds are so accomplished in flight, and that we may assume they have an extremely fine muscular sense. Besides, they migrate mostly in company, and an error in flight of one bird will be easily corrected by the others. But how do they hit the direction in flying away from the coast? They must be able to exactly measure the angle at which they ought to leave the land. Therein, of course, a qviite small error \\'ould involve great deflections from the proper course, but do we know that this does not actually occur often enough ? and may it not be supposed that in many cases corrections are made in the flight, as soon as any point of orientation again emerges in the circle of vision ? So much we at least know, that even on land birds wander not infrequently. And it is at least not demonstrated in any one of tJie cases cited by Mr. Newton, that the birds referred to appeared on those islands every year, nearly at the same time and in the same number. Mr. Newton adduces a second series of "facts" which seem to be against the sufficiency of the five senses ; but are these really facts ? The young, scarcely three months old, of many of our birds, are said to pursue their flight southwards in autumn alone. Is that certain ? and have we not here, perhaps, a too ready deduc- tion of general niles from a few well-observed cases? Mr. Newton even says : " This seems to happen with nearly all the accipitres," &c. He quotes a letter from M. Giitke, stating that in July "Young starlings pass over Heligoland by hundreds of thousands without a single old bird accompanying them." I confess that I cannot regard this as a fact, but as a more or less probable conjecture; for M. Gatke, though an excellent ornitho- logist could not possibly have inspected a hundredth part of tliese'" hundreds of thousands " of starlings flying about. I do not mean to assert that these or the other data are false ; they may well be correct. I merely hold that we must guard a<^ainst building far-reaching theoretical inferences on obser- vations the general validity of which is not in the least demon- strated. But even supposing that all these data are correct ; further, supposing it certain, that these young birds, which go forth alone, also actually find the route of the species with the same certainty as if they had known it long before, would these facts be explained by the supposition of a magnetic sense ? I think not. For in that case, what must have been born with the young bhd? Merely this magnetic sense? i.e., the power of directly perceiving external d rection in its own body? By no means. There must also be born with the young bird the consciousness of what angle to the magnetic meridian it must shape its flight at. But much more than this. It has been long known that birds, so long as they are migrating over land, frequently alter their direction ; hence, supposing the young bird to be guided by a mao-netic sense, there must be born with it the tendency to fly (say) twenty miles at an angle of 45° to the magnetic meridian, then 100 miles at an angle of 27°, and so on. That this is a physiological absurdity, no one would deny. For these reasons I hold that a special sense for direction does not exist in birds, and that the phenomena of migration, however wonderful they appear, yet cannot ultimately depend on magic (Zauberei), and in this Mr. Newton no doubt agrees with me. Hence, nothing remains but to try to explain these phenomena by the known physical and mental properties of birds ; for there is no third course. , . , ,, I shall be rejoiced if Mr. Newton succeed with this better ^j^j^Q j^ August Weismann Freiburg im Breisgau, March 31 The editor having afforded me the opportunity of seeing the foregoing remarks, it will, perhaps, be convenient to the readers of Nature that I should here add the comments I have to make upon them. I deeply regret if my criticism of Dr. Weismann s treatise or lecture be open to the charge of unfairness. I had no wish to misrepresent him, and I cannot see that I have been guilty of such an act — indeed, the -wide publication of his theory would render any attempt to do so futile. As to his acceptance of Dr. Palmen's conjecture for "absolute truths," I must urge that he took no exception to any of them, while, in the case of his Bernacle or Brent Goose, he especially adopted (p. 27) that route X which I had particular reason to consider unfounded. I did not assert that Dr. Weismann spoke of birds flying over the sea at the height of 20,000 feet, though there seems no reason why some might not, if they can do so over the land ; nor did I impute to him that they always keep land in sight. I had no need to declare my disbelief in Dr. von Middendorft's magnetic hypothesis, for I never met with any man that held it. I had spoken of it already elsewhere (E7icycl. Brit. Ed. 9, iii., p. ^(><)), and I considered it had been set at rest for ever by Prof. Baird in the article I cited. In like manner it seemed useless to disclaim any belief in the possession by birds of a "sixth sense" which is not common to ourselves and other animals. My only object was to show that Dr, Weismann's theory was inconsistent with certain facts, and nothing he has since adduced makes me think it otherwise. As to some of these "facts "he is incredulous, and I have no fault to find with his caution in this respect, but I am sure that the more he investigates them, the less he will be inclined to demur to them. I shall leave to the ornithologists of New Zealand the defence of those that relate to their cuckoos. Dr. Weismann will find in Mr. Jones's "Naturalist in Bermuda" (London, 1859) more than enough to justify my allegations in regard to the passage of Charadrius vir^itiicus (not Uuvialis) over those islands ; indeed^it has long been notorious ; and as to the plovers of the Sandwich group, I have not only to thank Capt. Long, R.N., for his confirmation {supra, p. 460) of my statements, but also Prof. George Forbes, who kindly informs me that when there, on the occasion of the transit of Venus, he shot scores of these birds, and that his friend Capt. Cator, R.N., of H.M.S. Scout, having sailed thence, was overtaken in mid- ocean by them, flying in a direct line for Vancouver's Island, on arriving at which he found they had already reached it. Con- cerning the "facts" relating to some young birds preceding their parents in migration, the more inquiries I make of well-placed observers the more satisfactory are the answers. For want of space I cannot here give the details, but I may just say that Mr. Cordeaux, who has been for many years a watchful observer of migratory birds on the Lincolnshire coast, has named to me nine species of Lif/ticolcr, of which he has personally assured himself that the young migrate apart from, and invariably arrive earlier than, the old— thus fully bearing out Temminck's assertion, made nearly forty years ago. The case of our cuckoo-, which 1 cited, is incontestable, and M. Gatke, I doubt. not, will satisfy any scruples about his starlings in that book which we are expecting from his hands. • , I will also take this opportunity of replying to Mr, Pringle s note {supra, p. 481). My chief reason for not referring to the matter of temperature was that we know too little of the power of birds to resist extreme cold to depend much upon it, and I thought I would not take up room by bringing in that question. Doubtless there is something in what he says touching the loom of land, but I fail to see how it will help very far, and especially in nocturnal flights. Alfred Newton Magdalene College, Cambridge, April 20 Colour in Nature I WISH to offer a few remarks upon Mr. Wallace's kind and appreciative review of my work on the " Colour-Sen^e' in Nature, vol. xix. p. 501. Mr. Wallace attributes to me "many errors " and inaccuracy as to matters of fact ; but I do not think the instances he alleges are sufficient t justify the statement. Had I said in every case what Mr. Wallace makes me say, I should, doubtless, have been misrepresenting facts ; but it seems to me that in most of the passages to which he refers he has slightly misconceived my meaning. I should not attempt to oppose so distinguished a naturalist on points of biological inference, but I venture to defend the accuracy of my statements of fact. . ., ,, I. " Scissirostrum Pagei does not ' belong to a family generally dull,' while it is itself decidedly dull-coloured. Ihe hr^t statement will be correct if we ^Xz-cs: Scissirostrum among the brilliant starlings ; but Mr. WaUace himself, following Prince April 2 \, 1879] NATURE 581 Lucien Bonaparte, puts it next to the West African Buphagtz. Now the Buphagcc are certainly dull birds, while Scisstrostriim is described in the " Malay Archipelago " as "almost entirely of a slaty colour, with yellow bill and feet, but the feathers of the rump and upper tail-coverts each terminate in a rigid glossy pencil or tuft of a vi\-id crimson" (i. 430). I wrote -nnth this passage of Mr. Wallace's under my eyes, and refer in a footnote to his volume for the vivid crimson. I did not say the bird was brilliant, I merely noticed the colour of its tail and beak. The case really stands thus : If Scissirostrum was differentiated from a generic ancestor generally resembling Buphaga, we have to inquire, why did it develop these ornamental adjuncts ? and my answer is, because while Buphaga pecks the parasites of the backs of mammals, Scissirostrum feeds oflf "grains and fruits." 2. "Santarem, of which it is said 'the pastiires are destitute of flowers, and also of animal life, with the exception of a few small plain-coloured birds,* is one of the richest localities for flowering shrubs in South America." Now, this passage to which Mr. Wallace takes exception is not mine, but is a textual quotation from Mr. Bates ("Naturalist on the Amazons," p. 183). It is given in inverted commas in my text, with reference to the original in a footnote. I was, of course, aware that the Brazilian woods generally were full of brilliant birds, and that "the butterflies in the adjacent forests were gorgeous in the extreme." What I wished to point out was that in particular spots like these meadows, where the general aspect of the flora was not bright, the purely local fauna was likewise dulL We may find great varieties in this respect nearer home in a meadow, an adjacent warren, and a moor or swamp behind it. Moreover, the passage was professedly quoted, simply as showing the general impression left upon my mind by reading various books of travel. May I add a sentence from a private letter of Mr. 