732 



GENERATION AND DEVELOPMENT. 



CORPUS LUTEUM OF MEN- 

 STRUATION. 



CORPUS LUTEUM OF PREG- 

 NANCY. 



At the end of 



three weeks 

 One month 



Two months 



Six months 



Nine months 



Three-quarters of an inch in diameter ; central clot red- 

 dish ; convoluted wall pale. 



Smaller ; convoluted 



wall bright yellow ; 



clot still reddish. 

 Eeduced to the condition 



of an insignificant 



cicatrix. 



Absent. 



Absent. 



Larger ; convoluted wall 

 bright yellow ; clot still 

 reddish. 



Seven-eighths of an inch in 

 diameter ; convoluted wall 

 bright yellow ; clot per- 

 fectly decolorised. 



Still as large as at end of 

 second month; clot fibri- 

 nous ; convoluted wall 

 paler. 



One-half an inch in diame- 

 ter ; central clot converted 

 into a radiating cicatrix ; 

 the external wall tolerably 

 thick and convoluted, but 

 without any bright yellow 

 colour. 



IMPEEGNATION OF THE OVUM. 



Male Sexual Functions. 



The fluid of the male, by which the ovum is impregnated 

 consists essentially of the semen secreted by the testicles ; 

 and to this are added, as necessary, perhaps, to its perfec- 

 tion, a material secreted by the vesiculae seminales, in 

 which, as in reservoirs, the semen lies before its discharge, 

 as well as the secretion of the prostate gland, and of 

 Cowper's glands. Portions of these several fluids are, 

 probably, all discharged, together with the proper secre- 

 tion of the testicles. 



The secreting structure of the testicle is disposed in two 

 contiguous parts, (r) the body of the testicle enclosed within 

 a tough fibrous membrane, the tunica alluginea, on the 

 outer surface of which is the serous covering formed by 

 the tunica vaginalis, and (2) the epididymis. The vas deferens, 



