RODENTIA. 383" 



The testicles are situated in the perineal region, below the anus. The 

 vesicul<e seminales are wanting, but the prostate is large, forming a con- 

 spicuous bulb around the origin of the urethra. Cowper's glands are wanting 

 in the dog, and are small in the cat. The penis of the dog is long, and termi- 

 nates in a point. In common with the camivora generally, a bone is found in 

 the penis ; its anterior extremity is fixed in the glans, while the posterior is 

 attached to the corpus cavernosum, occupying all that portion of the organ 

 which is lodged in the sheath. The os penis is long and curved, presenting an 

 inferior gutter, in which the urethra is placed, continuous with the groove of 

 the corpus cavernosum ; it favours the introduction of the penis into the vulva. 

 In the dog, the corpus spongiosum forming the glans undergoes a very remark- 

 able degree of tumefaction, which retains the two sexes in coitw for a con- 

 siderable time. The differences in the female organs are unimportant. In the 

 cat, the penal bone is not so well developed, and the penis, when relaxed, is 

 turned backwards ; when erect, it assumes the same position as in other car- 

 nivora. In the female, a small bone exists in the clitoris. The mammae are 

 arranged as in the sow. 



RODENTIA. 



The front teeth form one of the leading characteristics of the rabbit. The 

 iental formula is — 



. 2-2 0-0 3-3 3-3 „„ 



^•rrr '• O^'P-"'- 232' '^•333 = 28. 



The upper incisors consist of a large, curved, chisel-shaped pair, which grow 

 from permanent pulps ; they are covered with enamel only on their anterior 

 surface, which, wearing more slowly 

 than the rest, gives rise to the chisel- 

 like edge. The second pair of upper 

 incisors are situated immediately 

 behind the first, and are remarkably 

 small. The lower incisors resemble 

 in most respects the large upper 

 ones. 



There is an enormous diastema. show the arrangement of Eodent Teeth, 



Fio. 147. 

 Lateral half of Mandible of a Rabbit, opened to 



The molar and premolar teeth have 



compound transversely ridged tables, and grow from permanent pulps.^ 

 The large papillae of the tongue appear as two well-marked oval spaces, the 

 papillcB foliatcB, one on each side posteriorly, not upon the dorsum. Thes^ 

 contain the minute organs of taste, which occur in the larger papillte of the 

 horse's tongue. 



The stomach is simple in structure. The cmcum is long, being slender and 

 glandular at its termination. The liver and pancreas are both large, and the 

 pancreatic duct enters the intestine far behind the biliary duct. 



The testicle is large, ovoid, sometimes scrotal, sometimes abdominal in situa- 

 tion ; in the latter case it is fixed by the gubemuculum testis. The vai 

 deferens is so separated from the blood-vessels that the spermatic cord is 

 really double. The vasa discharge into the urethra on each side of the 

 duct of a large uterus masculinus, described by some authorities as a single 

 median vesicula seminali§. 



