122 IV. lO. 



in an upward direction ;^^ so that there must be an abundant 

 collection -of residual matter and of blood in the lower region, 

 that is to say in the neighbourhood of the excremental orifices. 

 Here therefore nature hag placed the mammae. For the part 

 whence they can most easily derive nutriment will clearly be 

 that part in which the nutriment is set in motion. In man 

 there are mammae in the male as well as in the female; but 

 some of the males of other animals are without them. Such 

 for instance is the case with horses, some stallions being destitute 

 of these parts, while others that resemble their dams have 

 them.^ Thus much then concerning the mammae. 



Next after the breast comes the region of the belly, which 

 is left unenclosed by the ribs for a reason which has already 

 been given ; ^^ namely that there may be no impediment to 

 the swelling which necessarily occurs in the food as it gets 

 heated, nor to the expansion of the womb in pregnancy. 



At the extreme end pf what is called the trunk are the parts 

 concerned in the evacuation of the solid and also of the fluid 

 residues. In all sanguineous animals with some few exceptions,^^ 

 and in all vivipara without any exception at all, the same part 

 which serves for the evacuation of the fluid residue is also made 

 by nature to serve in sexual congress, and this alike in male and 

 female. For the semen is a kind of fluid and a residue. The 

 proof of this will be given hefeifter, but for the present let it be 

 taken for granted. The like holds good of the menstrual fluid in 

 women, and of the part by which they give issue to it. This 

 also, however, is a matter of which a more accurate account will 

 be given hereafter. For the present let it be simply stated "as 

 a fact, that the catamenia of the female as also the semen of the 

 male are residual matter.^^ The catamenia, then, and the semen 

 are both fluid, and thus it is only reasonable that the same parts 

 which serve for voidance of the urine should give issue to these 

 residues, which have identical or similar characters. Of'.the internal 

 structure of these parts, and of the differences which exist between 

 the parts concerned with semen and the parts concerned with * 

 conception, a clear account is given in the book of Researches 

 concerning Animals and in the treatises on Anatomy. Moreover 

 I shall have to speak of them again when I come to deal with 

 Generation and Development. As regards, however,- the external 

 shapes of the parts, it is plain enough that they are adapted to their 

 689a. 



