272 VERTEBRATE ZOOLOGY 

 THE RABBIT 



Two or three specimens will be needed for a complete dissection, 

 one for the muscles and skeleton and one or two for the remain- 

 ing organs. For directions for killing and preserving them see 

 those for the cat (p. 205). 



External Characters. Observe the arrangement of the hair on 

 the body, which covers even the tip of the nose and the walking- 

 pads of the feet, only the nipples being bare. Note the difference 

 in the texture of the hair on different parts of the body ; it is usu- 

 ally longest and coarsest along the middle of the back. The 

 whiskers, or vibrissae, are tactile organs, and important to small 

 animals like rodents, which live more or less in confined places 

 and are nocturnal in their habits. Observe the color of the animal, 

 if it has any, and the differences in color between the different 

 regions of the body ; the back and belly, the head and trunk, the 

 inner and outer sides of the legs. 



Observe the general form and shape of the body. The trunk is 

 a laterally compressed, cylindrical structure ; the head is elongate, 

 and the characteristic incisor teeth, which mark the rodent, are 

 prominent ; the neck is short, and the tail is very short. The fore- 

 legs are short and weak, but the hind legs are very long and mus- 

 cular and enable the animal to progress by the peculiar leaping 

 gait which is characteristic of hares and rabbits. 



The body may be divided into four regions: the head, neck, 

 trunk, and tail ; the trunk, in turn, may be divided into the thoracic, 

 lumbar, and sacral subregions. 



The Head. This body region articulates with the vertebral 

 column by two occipital condyles. It is very solid and compact, 

 all the bones being closely knit together, and the upper jaw being 

 firmly joined with the cranium. This feature is correlated with 

 the structure of the teeth, which are not all alike in form, nor of 

 use mainly in seizing and holding the food, as is the case in most 

 of the lower vertebrates, but are specialized to perform a variety 

 of functions. Note carefully their form. The front teeth, or in- 

 cisors, have a chisel-like edge and are used for gnawing and cutting 

 (a function indicated by the name of the group) ; the eyeteeth, or 



