254 Descriptive Zoology. 



them, and bounties are continually paid for killing them ; 

 they thrive in spite of all that can be done. The intro- 

 duction of contagious diseases has not been a success. 



Uses of Rabbits. In this country they are used only for 

 food, and that to a very slight extent ; but in Australia and 

 some other parts of the world the fur is saved and used in 

 making felt. This is an important industry, as practically 

 all our " derby " hats are made of rabbit fur. Most of the 

 fur goes to London to be dyed. 



Development of the Rabbit. The ovaries are small ovoid 

 bodies attached to the dorsal wall of the abdominal cavity, 

 posterior to the kidneys. The eggs are microscopic, and 

 when set free from the ovary, enter the free opening of the 

 oviducts, as in the case of the frog. The posterior end of 

 each oviduct is developed into an organ called the uterus, 

 for holding and nourishing the egg, which is here retained 

 till development to the form of the parent is reached. The 

 young are born alive, and for a time after birth they are 

 nourished by milk from the mammary glands of the mother. 

 From four to seven are usually in a litter, more commonly 

 five or six. As several litters may be produced during a 

 year, the rate of their increase is very rapid ; but their fa- 

 talities are enough to keep their numbers down in this part 

 of the world. The little " cottontails " are concealed in a 

 fur-lined nest, which is a pocketlike hole in the ground. 



The Nervous System of the Rabbit. The brain is fairly 

 well developed, but the rabbit has not a high intelligence; and 

 as in the other lower orders, the surface of the brain is nearly 

 smooth instead of convoluted, as is the case with brains of 

 the higher animals. The principal parts of the brain are 

 the cerebrum, with its two hemispheres tapering forward 

 into the olfactory lobes (see Fig. 167). Back of the cere- 

 brum is the irregular cerebellum, with a central and lateral 



