42O 



The Urethra 



c. 



finger, which thus guides it to the meatus urinarius. In childhood 

 the meatus is, proportionately, very far back, and the sound is apt to 

 enter the vagina instead of the bladder. In case of doubt, a second 

 sound may be introduced into the vagina, or the finger into the 

 rectum. 



Development For a considerable period of its existence the 



fcetus remains sexless ; there is 

 a rudimentary penis or clitoris 

 (A, pc}, as the case may be ; 

 immediately below which is the 

 uro-genital orifice (c, ug). On 

 either side of this is a tegu- 

 mental fold (A, Is) ; should the 

 sex prove female, these folds 

 remain separate the labia 

 majora ; but, should a male be 

 developed, they fuse in front of 

 the anus (D, j), to form the 

 scrotum. The median ridge 

 upon the scrotum the raphe 

 shows where the folds have 

 joined. The lips of the uro- 

 genital sinus remain as the 



nympha? and enclose the clitoris above. The clitoris enlarges but 

 slightly. 'In the male the penis continues to enlarge, and the margins 

 of a longitudinal groove on its under surface gradually unite from the 

 primitive urethral orifice behind, as far forwards as the glans, so as to 

 complete the long canal of the male urethra, which is, therefore, a pro- 

 longation of the uro-genital sinus.' The corpora cavernosa, which are 

 at first separate, become fused together in the chief part of the penis, 

 but remain distinct against the pubes. In cases where the fusion of the 

 lateral halves of the body has been imperfectly accomplished, a deepish 

 dimple may persist in the skin of the middle line of the sacral or coccy- 

 geal region. Such a dimple is often associated with spina bifida. 

 Should the depression extend still more deeply, it might in time become 

 separated from the skin and remain as a closed sac beneath it ; then, 

 collecting epithelial elements in its interior, it would constitute a dennoid 

 cyst. Dennoid cysts are often met with in the sacro-coccygeal neigh- 

 bourhood. 



Amongst the commonest of the twenty-four malformations which 

 arise from arrest of development of these parts are the following : 



Hypospadias (wro, beneath ; o-Trau, tear), from the floor of the 

 urethra having been apparently ' torn ' away. As the distal part of 

 the canal is the last to be closed in, the deficiency is of more frequent 

 occurrence towards the glans than along to the root of the penis. Some- 

 times the entire length of the floor is undeveloped. The urethral fissure 



