THE GENERATIVE ORGANS. 237 



CHAPTER XVIII. 



THE GENERATIVE ORGANS. 



Preparation 1. Those parts which contain erec- 

 tile tissue will be best studied after having been 

 injected. Their bloodvessels and sinuses may have 

 been tilled in the animal which was injected entire 

 from the root of the aorta; but, if not, a special 

 injection from the lower end of the abdominal aorta 

 is to be made, the arteries supplying the lower limbs 

 being first tied to prevent waste of the injection. 

 The hardening of the parts in spirit must be effected 

 very gradually (the spirit being daily made stronger), 

 since otherwise the gelatine shrinks away from the 

 walls of the venous sinuses, and the preparation 

 becomes in great measure spoiled. The sections 

 which are made should some of them be mounted, 

 unstained, in dammar, others after being lightly 

 stained with logwood, so that the plain muscular 

 and fibrous tissue, and also, in sections including 

 the urethra, the epithelium of that tube may be 

 exhibited as well as the vessels. 



Preparation 2. Parts which have not been 

 injected are hardened in 2 per cent, bichromate of 

 potash solution (fourteen days), or per cent, chromic 

 acid (seven days), followed by spirit in either case. 



Preparation 3. The glandular organs, such as 

 the prostate and vesiculse seminales, are prepared 

 either with the per cent, chromic acid solution 

 followed by spirit, or with spirit alone. The subse- 

 quent processes of staining and mounting are the 

 same for all, except that it will be found, as a rule, 

 that those which have been in chromic acid stain 



