280 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



more brilliant hues, and often accompanied by an unusual 

 increase of size. Persons who are not acquainted with these 

 and many other facts adduced by Mr. Wallace would, lie 

 thinks, hardly realize their importance and significance. He 

 therefore illustrates them by supposing parallel cases to oc- 

 cur among the mammals. " We might have, for example, in 

 Africa the gnus, the elands, and the buffaloes all colored and 

 marked like zebras, stripe for stripe over the whole body ex- 

 actly corresponding. So the hares, marmots, and squirrels 

 of Europe might be all red, with black feet, while the corre- 

 sponding species of Central Asia were all yellow, with black 

 heads. In North America we might have raccoons, squirrels, 

 and opossums in parti-colored livery of white and black, so 

 as exactly to resemble the skunk of the same country; while 

 in South America they might be black, with a yellow throat- 

 patch, so as to resemble with equal closeness the tayra of 

 the Brazilian forests." 



With birds, however, the case is different, and among 

 them locality exerts a marked influence. One of the most 

 curious cases is that of the parrots of the West Indian Isl- 

 ands and Central America, several of which have white heads 

 or foreheads, occurring in two distinct genera, while none of 

 the more numerous parrots of South America are so colored. 

 The Andaman Islands are equally remarkable, at least six of 

 the peculiar birds differing from their continental allies in 

 being much lighter, and sometimes with a large quantity of 

 pure white in the plumage, exactly corresponding to what 

 occurs among the butterflies. In Celebes w r e have a swal- 

 low-shrike, and a peculiar small crow, allied to the jackdaw, 

 whiter than any of their allies in the surrounding islands. In 

 Timor and Flores we have white-headed pigeons, and a long- 

 tailed fly-catcher almost entirely white. In the small Lord 

 Howe's Island formerly lived a white rail (JSTotornis cdba), 

 remarkably contrasting with its allies in the larger islands 

 of New Zealand. 



Mr. Wallace has also published an important article on 

 the colors of animals, with criticisms on the theory of sex- 

 ual selection. 



Dimorphism. 



In an essay entitled "Antigeny, or Sexual Dimorphism in 

 Butterflies," published by Mr. S. H. Scudder in the Proceed- 



