GENERATION OF ANIMALS, I. xix. 



bloodless animals the analogous substance. And 

 since semen also is a residue from nourishment — from 

 nourishment in its final form, surely it follows that 

 semen will be either blood or the analogous substance, 

 or something formed out of these. Now every one 

 of the parts " is formed out of the blood as it becomes 

 concocted and in some Avay diWded up into portions ; 

 and though semen which has been concocted is by 

 the time of its secretion from it considerably different 

 in character from blood, yet unconcocted semen, and 

 semen emitted under strain due to excessively 

 frequent intercourse, has been known in some cases 

 to have a bloodUke appearance when discharged ; 

 and this shows that semen is pretty certainly a residue 

 from that nourishment which is in the fomi of blood 

 and which, as being the final form of nourishment, is 

 distributed to the various parts of the body.* This, 

 of course, is the reason why semen has great potency '^ 

 — the loss of it from the system is just as exhausting 

 as the loss of pure healthy blood — and this, too, is 

 why we should expect cliildren to resemble their 

 parents : because there is a resemblance between 

 that which is distributed to the various parts of the 

 body and that which is left over.** Thus, the semen 

 of the hand or of the face or of the whole animal really 

 is hand or face or a whole animal though in an un- 

 differentiated way ; in other words, what each of 

 those is in actuality, such the semen is potentially,^ 

 whether in respect of its o^\•n proper bulk, or because 

 it has some dynamis ^ within itself (I mention both 

 alternatives because from what we have said so far 

 it is not clear which is the correct one,^ i.e., whether 



' This will be settled during the remaining part of the 

 Book ; see especially ch. 21. 



91 



