JANUARY 15 



of this embarrassment of information. It is some 

 years since I listened with sympathy to Dr. Dorn 

 in his laboratory at Naples, confessing with a sigh 

 that he was outpaced ; that it would take six heads to 

 deal with the advance of knowledge, even in his special 

 branch marine biology. He lamented that Latin had 

 been abandoned as the language of science common to 

 all nations. At present the proceedings of learned 

 societies are published in so many languages that it 

 is impossible for one man to overtake what is important 

 in each. 



IV 



One of the phenomena most familiar to the field 



naturalist, which has hitherto baffled under- 

 Protective 



standing, seems to have received mterpreta- colora- 

 tion by a well-known American ornithologist, 

 Mr. Thayer. The design of protective coloration in 

 bird and beast is often sufficiently obvious. Even the 

 stripes of the tiger and the spots of the leopard have 

 been recognised by hunters as harmonising completely 

 with their surroundings in brilliant sunshine, while our 

 own partridge, ptarmigan, hare, and other creatures are 

 conveniently assimilated in hue to that of their usual 

 haunts. But nobody hitherto has hit upon the reason 

 why the underparts of terrestrial birds and mammals 

 are so often white or very light coloured. 



That this is part of a scheme of protective coloration 

 is perhaps the last idea that would occur to most 

 people. It would be much easier to account for it 



