CASES OF ADAPTATION 127 



work in the actual formation of new species at the present 

 time. The first is that of the Porto Santo rabbits, carefully 

 investigated by Darwin. In the history of an early Spanish 

 voyage it is recorded that, a female rabbit having had a 

 litter of young on board, they were all turned loose on this 

 small uninhabited island near Madeira. This was about 

 1419, and from these alone the island became fully stocked, 

 and remains so still, although the island is now fairly peopled. 

 Darwin was able to examine two of these rabbits preserved 

 in spirits, three others in brine, and two alive which had been 

 in the Zoological Gardens for four years. These seven 

 specimens, though caught at different times, closely resembled 

 each other ; they were all full grown, yet they were very much 

 smaller than English wild rabbits, being little more than 

 half the weight, and nearly three inches less in length. Four 

 skulls of the Porto Santo rabbits differed from those of 

 English wild rabbits in the supraorbital processes of the 

 frontal bone being narrower ; but they differed considerably 

 in colour, the upper surface being redder, and the lower 

 surface pale grey or lead colour instead of white ; the upper 

 surface of the tail, however, was reddish-brown instead of 

 blackish-grey as in all wild European rabbits, while the tips 

 of the ears had no black edging, as our rabbits always have. 



We have here a very remarkable series of differences in 

 size, colour, and even in the form of the skull ; while it was 

 noticed at the Zoological Gardens that they were unusually 

 wild and active, and also more nocturnal in their habits than 

 common wild rabbits. In this case, these rabbits would 

 certainly have been described as a distinct species if they 

 had been found in some more remote country to which it 

 was certain that they had not been introduced by man. 



Another example which shows nature at work, this time 

 in the actual process of " selection " of the better adapted 

 individuals, occurred quite recently. In February 1898, at 

 the Brown University, Providence, Rhode Island, after a very 

 severe storm of snow, sleet, and rain, 136 common sparrows 

 were found benumbed on the ground, and were collected 

 and brought to the Anatomical Laboratory. They were 

 laid on the floor of a warmed room to see if any of them 

 were alive, where after a short time 72 of them revived 



