GENITAL SYSTEM. 477 



call in to our assistance the abdominal muscles, by means of 



which the abdominal viscera will press upon the bladder and 



increase the expulsive efforts of its walls. We close the 



glottis at the very beginning of micturition, and then the 



vesical contraction is sufficient for the 



expulsion of urine. But towards the end 



of micturition, in order to expel the last 



drops, a renewed effort is necessary : the 



lowest portion of the bladder being fixed 



and concave, we could not evacuate it 



completely, unless, by the aid of the 



abdominal muscle, we compress the 



upper against the lower portion of the 



bladder in such a way as to completely 



obliterate the cavity (Fig. 130) ; in man, 



then, the bladder when completely 



emptied (not so, however, with all ani- Fi g- JJ^- JjJjfJ"J m of 



iimls) resembles a cup, and in this form 



it is seen in the dead body when this reservoir is completely 



empty. 



As soon as the bladder has been emptied, the walls of the 

 urethra are brought in contact and expel its contents; but 

 when this canal is diseased and long-seated inflammation has 

 destroyed the elasticity of the bladder, it is not thoroughly 

 emptied, and the urine remaining in contact with the mucous 

 suri'ace, contributes to keep up the pathological condition. 



II. GENITAL SYSTEM. 

 I. MALE ORGANS OF GENERATION. 



THE male organs of generation are composed of a gland 

 (testicle) and a series of excretory ducts. 



1. The male gland, the testicle^ is the offshoot from an 

 organ which is developed on the inner edge of the Wolffian 

 body (see above) ; until the close of the second month this 

 body presents no characteristic feature that would lead us to 

 know whether it were a testicle or an ovary ; but towards 



* This diagram shows how the bladder is completely emptied. 



1, Outline of the bladder when distended by a liquid. 2, 3, 4, 5, Represents 

 the outline of the bladder when reduced by different intensities of its contrac- 

 tions. 6, Represents the outline when the abdominal muscles have adjusted the 

 upper to the lower concave portion. The arrow indicates the direction in which 

 the compression is made. 



