166 THE DISEASES OF THE DOG. 



tion this part possesses two distinct erectile enlargements, 

 an anterior and a posterior. The first is analogous to 

 that of the glans penis of the horse, and is formed by an 

 expansion of the erectile tissue of the urethra ; club-shaped 

 at its anterior base, it has there a point suddenly bent 

 downwards, beneath which is pierced the urethral orifice ; 

 posteriorly it is thin and partially covers the other erectile 

 mass. The latter is supplementary ; it begins at the base 

 of the free portion of the peniV-where the integument of 

 the sheath is folded in a circular manner around it. From 

 one toone and a half inches long;: it embraces the upper 

 border and sides of the zone ; pyramidal in shape, its base, 

 which is posterior, is three quarters to one and a quarter 

 inches thick ; in front it thins away beneath the erectile 

 tissue of the head. Such are the two erectile masses, 

 Whose summits overlap, so that the' free portion of the 

 penis, bulging in front and still more so behind, is nar- 

 rowed in the middle. Although contiguous, these two 

 vascular dilatations are independent of each other ; the 

 posterior has, likewise, no communication with the corpus 

 cavernosum, and possesses two particular veins, which pass 

 backwards in a lateral groove. Each is erected separately 

 during copulation, when they assume a large size ; the 

 great volume of the posterior enlargement prolongs the 

 duration of this act, until flaccidity ensues. This pecu- 

 liarity is a consequence of the absence of the seminal 

 reservoirs." The familiar spectacle of a pair of dogs 

 " locked" in coition is a consequence of the presence and 

 physiological peculiarities of the posterior of these enlarge- 

 ments (Blaine attributed to the clitoris a share in pro- 

 ducing it). When the male animal prematurely becomes 

 moved from his natural position on the female the dilata- 

 tion of the posterior part of the glans retains the penis in 

 the vagina, and it often becomes twisted on its narrow 

 part behind the bone, and bent backwards. This state of 

 affairs .must remain until the turgescence subsides, and 

 any attempt to forcibly separata the animals is liable to 

 lacerate the erectile walls of the vagino-vulval passage or 

 to injure the penis, the parts of the bitch rather than 



