GENERATION OF ANIMALS, I. xix.-xx. 



ever, this is a morbid condition, and that is why it 

 only occurs infrequently and in few subjects. It is 

 what occurs generally that is most in accord with 

 the course of Nature. 



By now it is plain that the contribution which the 

 female makes to generation is the matter used therein, 

 that this is to be found in the substance constituting 

 the menstrual fluid,'' and finally that the menstrual 

 fluid is a residue. 



There are some who think that the female con- XX 

 tributes semen * during coition because women some- 

 times derive pleasure from it comparable to that of 

 the male and also produce a fluid secretion. This 

 fluid, however, is not seminal ; it is pecuUar to the 

 part from which it comes in each several individual ; 

 there is a discharge from the uterus, which though 

 it happens in some women does not in others.'' Speak- 

 ing generally, this happens in fair-skinned women '^ 

 who are typically feminine, and not in dark women 

 of a masculine appearance. Where it occurs, this 

 discharge is sometimes on quite a diiFerent scale from 

 the semen discharged by the male, and greatly ex- 

 ceeds it in bulk. Furthermore, differences of food 



his death. We know now that the menstrual bleeding is a 

 phase in the sexual cycle, this phase being usually succeeded 

 by the periodical liberation of the egg from the ovarj', and 

 by its attachment (if fertilized) to the wall of the uterus. 



* The view that the female also contributed semen was 

 apparently adopted by the Epicureans ; see Lucretius 

 iv. 1229 semper enim partus duplici de semine constat ; 

 cf. 1247, 1257-1258. 



' This apparently refers to the so-called vaginal discharge, 

 which is a natural secretion {cf. 739 a 37); but the latter 

 part of the paragraph seems to describe leucorrhoea, which 

 is pathological. The two have apparently been confused. 



" Cf. H.A.BBSsL 11. 



101 



