November io, 1910] 



NATURE 



4:-? 



he fur of the winter-whitened stoat, as well as in the 

 : :rmanently white polar bear. 1 think Mr. Mudge's 

 bservations are a distinct help to us in getting at the 

 leaning of these white coats. I should like to see what 

 \Iiss Sollas can do with the hair of the variable hare, as 

 in the whitened specimens of this animal I have never 

 5een any trace of the yellow tints found in the stoat. 



Mr. Mudge's note that the white areas of a piebald 

 nouse can be turned pink by immersion in 5 per cent, 

 itric acid in 78 per cent, spirit, but only in summer or 

 ; warm temperature, is also of great interest. Does it 

 r.QX. suggest a reason why pink colour in feathers is mostly 

 • und in summer plumages and in warm climates? And 

 - not his production of brown in the hairs of white rats 

 exposed to damp warm weather comparable with the well- 

 known saturated tints so prevalent in animals living 

 naturally in damp but warm countries? 



While writing on winter whitening it may be well to 

 direct attention to another point, which has always been 

 difficult to explain on physiological grounds, namely, the 

 fact that the black ear tips of the hare and the black tail 

 tip of the stoat are not subject to winter whitening. This, 

 however, would be explicable if, whereas the general 



THE SUBANT ARCTIC ISLAXDS OF NEW 

 ZEALAND^ 



'T'HE naturalists of New Zealand have always shown 

 •* themselves eager to take advantage of any oppor- 

 tunity for extending our knowledge of the fauna and 

 flora of their countr)'. Such opportunities are pre- 

 sented from time to time by the periodical official 

 visits of the Government steamer to the outlying 

 islands. In November, 1907, the s.s. Hinemoa de- 

 posited a large party of New Zealand men of science 

 on Auckland and Campbell Islands, calling for them 

 again on her return trip more than a week later. 

 The expedition was undertaken at the instance of the 

 Philosophical Institute of Canterbury, primarily for 

 the purpose of extending the magnetic sur\'ey of New 

 Zealand to the outlying southern islands, but the 

 volumes before us consist chiefly of zoological and 

 botanical observations, though there are also articles 

 on geophysics and geology. 



The work has been issued under the editorship of 



body coat of both these animals is cast twice a year, the 

 black hairs on the ears and tail are renewed only once 

 a year. If they are renewed only once they must remain 

 {apart from fading) of the same colour throughout the 

 year. That such a single moult is possible, and even 

 |MX>bable, in these two instances is shown by the fact that 

 in the squirrel there are two moults of the general body 

 coat, but only one of the ear tufts and tail hairs. 

 Similarly in the Equidae (according to Ewart), there are 

 two moults of the general coat but one only of the mane 

 and tail. G. E. H. Barrett-H.wiiltox. 



Jiilmanock House, Campile, Co. Wexford, 

 Ireland, November 3. 



Helium and Geological Time. 

 1 MUST apologise for an error in my letter published in 

 Nature of November 3. The sixteenth line and onwards 

 should read "... for we have no knowledge of chemical 

 aflSnity between helium and solid substances ; while, in 

 respect of solubilitv, it would probablv be inferior to the 

 Other gases." ' R. j. Strutt. 



Imperial College of Science, South Kensington. 

 NO, 2 141, VOL. 85] 



Dr. Charles Chilton, and the publication has been 

 rendered possible by a substantial subsidy from the 

 New Zealand Governinent. It comes at an opportune 

 moment, and acquires a special interest in relation 

 to the exploration of the Antarctic continent now in 

 progress. 



The time at the disposal of the expedition was, of 

 course, all too short for a complete biological survey, 

 and the collections were evidently, at any rate in 

 many cases, ver\- fragmentary-, but many verj' interest- 

 ing results were obtained. The zoologists were un- 

 doubtedly right in devoting most of their energies to 

 the terrestrial fauna, which is much more likely to 

 be modified or even exterminated by human agency 

 than the marine fauna, but we cannot help wishing 



1 The Subantarctic Islands of New Zealand. Reports on the Geo-Physics, 

 Geology, Zoology, and Botany of the Islands lying to the South of Neur 

 Zealand. Based mainlv on Observations and Collections made daring an 

 Expedition in the Government Steamer Hinemoa (Capl. \. Belloius) in 

 November, 1907. ExUted by Pr if. Charles Chilton. Vol. L, pp. XXXV+3S8 ; 

 vol. iL, pp. 389-848. (Wellington, N.Z. : Philosophical Institute of Can- 

 terbury. London ; Dulan and Co., Ltd., 1909.) 2 vols. Price ^-u. net. 



