a48 THE PHYSIOLOGY OF REPRODUCTION 



placed one on each side of the urethra and extending throughout 

 the whole length of the structure. 



The fact that the fiUform prolongation is an erectile organ 

 points to the conclusion that its function is insertion into the os 

 uteri during copulation. An examination of the uterus in the 

 sheep shows that the os, when open, is fully large enough to 

 admit of the entrance of the distal portion of the penis in the 

 region of the glans. If the extreme distal end does so enter, 

 the fihform process must extend into the cavity as far, or 



Fibr. Cart 



Fig. 62. — Transverse section through filiform appendage of ram, about 

 a quarter its length from the tip. x 45. 



Bl. v., blood-vessels; Ep. Ur., epithelium surrounding urethral cavity; 

 Fibr. Cart., fibro-cartilage ; Int.. integument; Muse, muscular layer; 

 Ur., urethra. 



nearly as far, as the junction of the relatively short corpus uteri 

 with the two cornua. That the appendage functions in the 

 manner described seems additionally probable in view of the 

 fact, to which sheep-breeders attest, that if the process is cut 

 off the ram is rendered barren. Professor Robert Wallace 

 informs me that it used to be a regular;^ practice, for the pro- 

 tection of ewes while being driven south from the Highlands of 

 Scotland, to cut off the filiform appendage from the rams to 

 prevent them from impregnating .the ewes on the way, this 

 method of inducing sterility proving quite as effective as removal 

 of the testicles. 



