MALE ELEMENTS OF GENERATION. 323 



developed in the testicle itself, mixed with the secretion of 

 the vasa def erentia, of the vesiculee seminales, of the glands 

 of the prostate, and of the glands of the urethra. As we 

 shall see when we come to discuss the mechanism of fecunda- 

 tion of the ovum, the spermatozoids are the essential male 

 elements, and these are produced in the substance of the tes- 

 ticle, by a process analogous to that of the development of 

 other true anatomical elements, and not by the mechanism 

 with which we are familiar in secreting glands. The testicles 

 cannot be regarded strictly as glandular organs. They are 

 analogous to the ovaries, and are the only organs in which 

 spermatozoids can be developed, as the ovaries are the only 

 organs in which the ovum can be formed. If the testicles 

 be absent, the power of fecundation is lost, none of the fluids 

 secreted by the accessory organs of generation being able to 

 perform the functions of the true fecundating elements. 



In the healthy male, at the climax of a normal venereal 

 orgasm, from half a drachm to a drachm of seminal fluid is 

 ejaculated with considerable force from the urethra, by an 

 involuntary muscular spasm. This fluid is slightly mucilagi- 

 nous, grayish or whitish, streaked with lines more or less 

 opaque, and evidently contains various kinds of mucus. It 

 has a faint and peculiar odor, sui generis, which is observed 

 only in the ejaculated fluid and not in any of its constituents 

 examined separately. It is a little heavier than water, and 

 does not mix with it or dissolve. After ejaculation, it be- 

 comes jelly-like and dries into a peculiar, hard mass, which 

 may be softened by the application of appropriate liquids. 

 The liquid is not coagulated by heat and does not contain al- 

 bumen. Its reaction is faintly alkaline. It contains, in the 

 human subject, from 100 to 120 parts of solid matter per 

 1000. 1 



The chemical constitution of the semen has not been very 

 thoroughly investigated and does not present the same physi- 

 ological interest as its anatomical characters. Aside from 



1 ROBIN, Le$ons sur les humeurs, Paris, 1867, p. 366. 



