TEE BEHAVIOUR OF BLIND ANIMALS. 345 



at the mercy of his enemies, and yet not to the degree one might have 

 supposed on account of his greater caution as well as the fact that his 

 senses of touch and smell make up so fully for the lack of sight. It 

 must be borne in mind that the olfactory tracts of the central nervous 

 system in the rat are highly developed and their association-paths 

 numerous, so that in an eminent degree the rodent, and especially the 

 rat, is worked, so to speak, as an entire mechanism largely through the 

 reflex paths of smell. 



One of the unexpected results of sudden blindness in the case of 

 white rats, whether affecting one or both eyes, was a most marked 

 alteration in disposition. Eats that were perfectly tame became at once 

 ferocious ; it was unsafe any longer to attempt to handle them as f or- 

 merfy, or to remove anything from their cage, for in an instant they 

 seemed aware of the approach of one's hand and were not only ready 

 but able to pounce upon it at once; even metal forceps were seized by 

 the teeth. After a considerable period in a rat blind in both eyes this 

 ferocity disappeared, but not so, or to but a slight extent, in those 

 lacking the power of vision on only one side. 



In our experience in the breeding of white rats, it is rare for the 

 female to devour her young, but invariably have those blind white rats 

 killed and eaten to a greater or less extent every litter they have had, 

 though placed under circumstances exactly similar to those of the intact 

 rats. 



Babbits. My opportunities to observe this species of rodent when 

 blindness was found on one or both sides, has been almost as good as in 

 the case of the rat. The differences noted in the animals is considerable. 

 A rabbit totally blind behaves in general much like a rat similarly 

 defective, but he shows less tendency on occasion to retreat towards his 

 place of safety, is less alert and apparently less prepared to meet emer- 

 gencies. But the readiness with which he manages to avoid obstacles 

 in his path is striking. He also, like the rat, stretches out his neck, 

 rises sometimes on his hind legs, but more frequently raises the fore 

 parts of his body into the air, all with the obvious purpose of exploring 

 the nature of his environment to a degree and with a frequency not 

 witnessed in the normal rabbit. Such an animal is, however, more 

 likely to fall under the power of his enemies than is the rat, though so 

 long as food is plenty near his burrow the wild animal would no doubt 

 develop that caution and use his other senses to such an extent that he 

 would generally escape ; but that he would in the long run fall a prey to 

 some wily fox seems more than probable. 



I have noticed no change in disposition in the case of the rabbit akin 

 to that in the rat and none of the blind specimens has had young. 



Neither the rabbits nor the rats ever make the mistake of walking 

 off a place elevated above terra firma. As I have elsewhere pointed out, 



