IOO



Notices of New Books, etc.



thought that the edition is limited to 300 copies, and therefore,

with the passage of time, the value of the book will increase.


A. G.B.



Geographic variation in Birds with especiae reference to the

EFFECTS of humidity, by C. Wieriam Beebe, Curator of Birds,

pp. 1 — 41 with five plates (figs. 1—6) from Scientific Contributions of

the New York Zoological Society.


This is a most interesting and instructive paper tending

to show that moisture has a deepening and intensifying effect

upon the colouring of animals—a truth which, if I remember

rightly, the experiments of Mr. Merrifield some years since with

various British species of Geometrid Moths appeared also to

support.


I11 Part I of his paper Mr. Beebe quotes from various

authorities to show what different views they hold respecting the

action of climatic and environmental conditions upon colouring,

sometimes correlated with a difference of size. With regard to

the seasonal dimorphism of various Lepidopterous insects referred

to in this chapter, I have argued (Proc. Zool. Soc. 1904, vol. II.,

pp. 142—4) that, inasmuch as wet, dry, and intermediate phases

of a species occur and interbreed at the same season in some

very dry climates, it is probable that they existed originally as

simple variations ; and were adapted, through elimination of the

unfit, to the seasons or climates to which the}' had gradually

migrated. This view is, moreover, strengthened by the known

fact that the wet and dry phases of Catopsilia (C. pomona and C.

crocale with their intergrades) occur and interbreed at all seasons

in India, the differences between them being of no value for pro¬

tective purposes. Thus, although experiment may affect the

pigmentation, it only reproduces variations originally unaffected

by the climate in which they lived.


Part II., dealing with dichromatism, is a chapter of con¬

siderable interest, and particularly that portion of it which treats

of Chen liyperborens and C. ccerulescens ; but those who wish to

comprehend the changes of colour in birds must read the article

for themselves. While studying it I wondered if the little Wax-

bill Sporoeginthus mclpodus had really acquired a female with “no



