RELATIONS OF THE ORGANS TO ONE ANOTHER. 599 



one, and consequently the products which they form are typical, just 

 the same as the salivary glands yield one specific secretion and the pan- 

 creas another. There are not any essential differences between these 

 processes. We should be making a sad mistake if we were to consider 

 the function of the cells of the mammary glands by itself. We are 

 able to understand it only when we trace its phases from a general stand- 

 point. The cells of the mammary glands take up from the blood, or 

 more directly from the lymph, certain substances which evidently must 

 be transformed completely, and to a certain extent assimilated, in order 

 to form the product which it will subsequently give up. Recent inves- 

 tigations indicate that even the actual process of secretion is not different 

 from that of other glands, for here also, after the secretion has been given 

 up by the cells, a residue of protoplasm and nucleus remains, and a new 

 formation of the same secretion again ensues. 



It is not alone the mammary glands that are dependent upon the sexual 

 apparatus. More and more we become cognizant of the fact that the 

 different parts of the latter stand in a number of different relations to 

 other organs, though we are not able to discover the nature of the active 

 principle any more definitely. We know at present merely of isolated 

 facts which we cannot explain satisfactorily. The different female sexual 

 organs are, in the first place, related to one another. As an example of 

 this, we need only cite the influence of the ovaries, when they are exerting 

 their normal function, upon the uterus, and especially upon the mucous 

 membrane of the uterus at the time of menstruation. Here again we 

 frequently find this attributed to nervous excitement, although there is 

 no definite proof that such is the case. The experiments of Halban l 

 have shown that the ovaries can exercise their function when there is no 

 connection with the nervous system. He showed that if he extirpated 

 the ovaries from young guinea pigs and inserted them at another part of 

 the body, the development of the external genitals took place exactly as if 

 the ovaries had remained in their original position. On the other hand, 

 in immature animals in which the ovaries had been completely removed 

 from the body, there was a halt in the development of the external organs 

 of generation. It is also well known that when the function of the 

 ovaries ceases, whether due to their ablation in a mature condition, or to 

 the fact that they have reached the end of the period of their activity, 

 changes take place in the uterus corresponding to a retrogression. 



Similarly the male organs of generation stand in relation to one another. 

 This is already evident from the way the cells of the testes work together 

 with those of the prostate gland, although this may be explained as a 

 result of a common stimulation. There are observations according to 

 which the prostate atrophies after the removal of the testes. 



1 Monatschr. f. Geburtshilfe u. Gynakol, 12, 496 (1900). 



