The Zoologist/4th series, vol 5 (1901)/Issue 725/Editorial Gleanings

by editor W.L. Distant

 

EDITORIAL GLEANINGS.

 

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In the 'Quarterly Journal of Microscopical Science,' Dr. W.G. Ridewood has published a most valuable paper "On the Structure of the Hairs of Mylodon listai, and other South American Edentata." We are glad to see that Dr. Ridewood is dissatisfied with the present composition of the order Edentata, which, as he remarks, will probably prove to be an unnatural assemblage of animals, and that, acting on further knowledge, it will probably prove necessary to remove the Old World forms Manis and Orycteropus to constitute two new orders by themselves. The diagnoses of hair-structure given in this communication are of too technical a nature for reproduction in our pages; but the publication has prompted a paper by Mr. R. Lydekker in 'Knowledge' on "Plant-bearing Hair," of which we cannot do better than give the following abstract:—

The author remarks that, "apart from its extremely coarse and brittle nature, the most striking peculiarity of the outer hair of the Sloths is its more or less decidedly green tinge.... Now green is a very rare colour among mammals, and there ought therefore to be some special reason for its development in the Sloths. And, as a matter of fact, the means by which this coloration is produced is one of the most marvellous phenomena in the whole animal kingdom—so marvellous, indeed, that it is at first almost impossible to believe that it is true. The object of this peculiar type of coloration is, of course, to assimilate the animal to its leafy surroundings, and thus to render it as inconspicuous as possible; and, when hanging in its usual position from the under side of a bough, its long, coarse, and green-tinged hair is stated to render the Sloth almost indistinguishable from the bunches of grey-green lichens among which it dwells. In the outer sheath of the hairs of the aï there are a number of transverse cracks, and in these cracks grows a primitive type of plant, namely, a one-celled alga. In the moist tropical forests forming the home of the Sloths the algæ in the cracks of their hair grow readily, and thus communicate to the entire coat that general green tint which, as already said, is reported to render them almost indistinguishable from the clusters of lichen among which they hang suspended."

Mr. Lydekker adds some weighty remarks in his paper. "It is quite clear that an alga would have been of no advantage to the Sloths until they had acquired their present completely arboreal kind of life, and, since there is a considerable probability that both types of these animals were independently derived from some of the smaller Ground-Sloths, it follows that on two separate occasions an alga has independently taken advantage of this suitable vacant situation, and adapted itself to its new surroundings. This difficulty, like the one connected with Sloths, having flourished before they acquired a lichen-growth, may appear of little importance to those who are convinced of the all-sufficiency of natural selection, but to others it may (if wellfounded) seem more serious."

 

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In the Proceedings of the Asiatic Society of Bengal (August, 1901), Miss Nelly Evans has contributed "Some Observations on the Life-History of Culex fatigans, the Common Grey Mosquito of Lower Bengal." The paper gives detailed evidence with regard to the female of this species of Mosquito—(1) that it may live, in its adult or imago stage, for nearly five weeks; (2) that during its adult life it may feed as many as five times; and (3) that it does not feed indiscriminately, but has a preference for the blood of the House-Sparrow, refusing that of Java-Sparrows, Larks, Rails, and White Rats. All these facts, but the last one in particular, are considered to favour the possibility of the insect being a carrier of a definite blood-infection, and to support the conclusions of Ross based upon experiments with this species of Mosquito.

 

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We learn from Melbourne that it has been decided to form an "Australasian Ornithologists' Union." The objects of the Society are the advancement and popularization of the science of ornithology, the protection of useful and ornamental avifauna, and the editing and publication of a magazine or periodical to be called The Emu, or such magazine or periodical as the Society may from time to time determine upon. The President-Elect is Col. W.V. Legge, R.A., F.Z.S., &c., and the Hon. Secretary, D. le Souëf, C.M.Z.S., M.B.O.U., &c.

We have now received Part I. of The Emu, a publication which will prove a very important factor in a knowledge of Australasian ornithology. It is well illustrated, and among its contributors are many well-known names.

 

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In Mr. John Morley's panegyric on Gladstone, at the recent unveiling of that deceased statesman's statue at Manchester, is an interesting statement of the mental platforms of Gladstone and Darwin. Mr. Morley, after describing the many mental gifts and activities of his master, went on to remark:—"No doubt something was left out in the wide circle of his interests. Natural science, in all its speculations and extensions and increase of scientific truth, extension of scientific methods—all that, no doubt, constitute the central activities, the intellectual activities, of England and Europe during the last forty years of his life—to all that he was not entirely opened. I remember once going with him one Sunday afternoon to pay a visit to Mr. Darwin. It was in the seventies. As I came away, I felt that no impression had reached him; that that intellectual, modest, single-minded, low-browed lover of truth—that searcher of the secrets of nature—had made no impression on Mr. Gladstone's mind, that he had seen one who, from his Kentish hill-top, was shaking the world."

 

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Mr. W. Eagle Clark, writing in the Auk (October last) states that the occurrence of a third example of the so-called Mealy Redpoll in the Island of Barra, one of the Outer Hebrides, incited him to procure the specimens, with a view to ascertaining to what species or subspecies of Acanthis the birds obtained in this far western island belonged. He found that all three examples were referable to the form described by Dr. Stejneger as Acanthis linaria rostrata (Coues)—a bird not hitherto recorded for Great Britain, though several specimens have been obtained on islands off the west coast of Ireland.

 

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In the American Naturalist for October last, Prof. W.M. Wheeler has concluded his series of papers on "The Compound and Mixed Nests of American Ants." The author has arrived at the same conclusion as Wasmann, that there are no evidences of ratiocination in Ants.Prof. Wheeler, however, remarks that this conclusion, "even if it be extended so as to exclude all animals except Man from a participation in this faculty, does not imply the admission of a qualitative difference between the human and animal psyche, as understood by Wasmann. Surely the sciences of comparative physiology, anatomy, and embryology, not to mention palæontology, distribution, and taxonomy, must have been cultivated to little purpose during the nineteenth century if we are to rest satisfied with the scholastic definition of ratiocination as an adequate and final verity. And surely no one who is conversant with modern biological science will accept the view that the power of abstract, ratiocinative thought, which is absent in infants and young children, scarcely developed in savages, and highly developed and generally manifested only in the minority of civilized man, has miraculously sprung into existence in full panoply like the daughter of Jove."