284 THE PHYSIOLOGY OF REPRODUCTION 



not possible that the effects which are usually ascribed to a 

 hypothetical " internal secretion " of the testis are partly due 

 to such a direct connection with the metabolism of the body ? 



The nature of the influence which the sexual glands exert 

 upon the metabolism of the body is very complex, and has not 

 yet been fully cleared up. Various observers have obtained 

 very contradictory results. Since this subject will be dealt 

 with in another chapter, we will refer to it here only in so far 

 as it has any bearing on the calcium and phosphorus metabolism. 

 On this point there is conclusive evidence of a morphological 

 nature both for the male and for the female organism. Castra- 

 tion leads to a marked increase in the growth of the long bones. 

 This fact, which is due to a retardation of the process of endo- 

 chondral ossification taking place in these bones, accounts for the 

 increase in stature of eunuchs and of castrated animals (see p. 306). 



Similar evidence, although of a more complex character, is 

 afforded in the case of the female by the relationship which 

 undoubtedly exists between the ovaries and osteomalacia, a 

 disease consisting mainly in a decalcification of the bones. It 

 is produced probably by an abnormal function of the ovaries, 

 since removal of the ovaries markedly improves, and sometimes 

 cures, this condition (see p. 353). In pregnancy and parturition 

 there is what one might call a " physiological osteomalacia " of 

 the pelvic bones ; and the activity of the mammary gland during 

 lactation must necessarily bring about an increased calcium meta- 

 bolism, since milk contains a very large amount of this element. 



The organic substances in the semen may be divided into 

 two groups. If the semen is examined microscopically it is 

 found that it contains, on the one hand, cellular elements viz. 

 the spermatozoa and lymphocytes, partly in a state of de- 

 generation ; on the other hand, organic material which is partly 

 amorphous and partly crystalline. 



The amorphous material consists of : 



1. Fine albuminous granules intermixed with a few fat 

 globules and pigmented granules. 



2. Small globules of about half the size of a red blood- 

 corpuscle consisting of a lipoid substance. 



3. Oval amyloid bodies composed of concentric layers. 

 These are, however, not invariably found. 



