DEVELOPMEXT OF THE FCETUS. 113 



and pubic portions of the muscular tissue now become the " cremaster" 

 muscle, while the sac of peritoneum carried down with the testicle 

 is converted, by obliteration of the neck, into the tunica vaginalis 

 testis. 



In Solipeds tlie testicles do not usually descend into the scrotum until 

 six months after birth ; when one or both do not appear, as sometimes 

 happens in the male domesticated animals, and remain in the abdo- 

 minal cavity during life, the gubernaculum, or what corresponds to it, 

 is reduced to a small thin cord, without a trace of cavity, and showing 

 only some few pale fibres of the atrophied cremaster muscle. In the 

 Foal they are voluminous, and somewhat reddish in colour ; they are 

 occasionally found in the scrotum at birth ; but they soon ascend into 

 the abdomen, to redescend during the first year. With some animals, 

 however, as has been already mentioned — and far more frequently with 

 the Horse and Pig than any othei's — the testicles remain in the abdomen 

 during life, or only one descends to its natural situation. When they 

 remain in the abdominal cavity, the animal is said to be " anorchid " or 

 " cryptorchid ;" and it has been shown that, although such animals 

 have the sexual propensity well marked, yet they are unproductive ; 

 their semen does not contain any spermatozoa. 



When one testicle has migrated to the scrotum, leaving one in the 

 abdomen, the Horse is " monorchid," and possesses the power of re- 

 production unimpaired. 



In Ruminants the testicles are small, and are in the scrotum at birth, 

 where they remain. Sometimes there is a strange malposition of the 

 testicles, and especially in the Pig, they having been found beneath the 

 chin, in the flank, and elsewhere. 



In the female, the ovary is derived from the genital gland, whose 

 anatomical elements are disposed so as to form the stroma. Graafian 

 follicles, and the ova. 



In fcetal Solipeds the ovary is of an immense size, especially about 

 the middle of gestation, and its stroma is red and extremely soft. 

 In other animals, and particularly liuminants, this disproportion is not 

 observed. 



The Fallopian tube and its pavilion are formed by the anterior portion 

 of Miiller's duct, the extremity of which presents a small linear orifice. 

 The uterus and vaijina arise from theposterior part of these ducts, whicli 

 approach each other, and finish by amalgamating posteriorly to form a 

 single canal. This fusion originates the vagina and body of the uterus, 

 the two diverging portions of the ducts comprised between the point of 

 union and the Fallopian tubes forming the uterine cornua. The uterus 

 and vagina are at first continuous and without any sign of demarcation, 

 but towards the sixth month the neck of the uterus begins to become 

 apparent. 



The external organs of tlie female in their indifferent state demand 

 notice. The intestine terminates in the cloaca, a cavity into which not 

 only this tube but also the bladder enters, through the uro-genital sinus. 

 This arrangement ceases somewhat suddenly, by the development of a 

 transverse septum that divides the cavity into two portions — the anal 

 opening, and the uro-genital orifice. -Vt the lower end of the latter 

 appears the genital tubercle, the rudiment of the penis or clitoris, and 

 which is surrounded by cutaneous ridges — the genital folds. This 

 tubercle increases in size, and is traversed by a groove or fissure 



8 



