MOVEMENT OF ANIMALS, xi. 



each contains vital moisture]." The reason for this as 

 regards the heart is plain, for it contains the origins 

 of the senses. That the generative organ is of the 

 same nature is shown by the fact that the seminal 

 force comes forth from it, being as it were a hving 

 thing. ΝοΛν it is only in accordance with reason that 

 movements are set up both in the central origin by 

 the parts and in the parts by the central origin, 

 and thus reach one another. Let A be the central 

 origin ; the movements at each letter in the diagram 

 drawn above ^ reach the central origin, and from the 

 central origin, Avhen it is moved or undergoes change 

 (for it is potentially many), the origin of movement 

 in Β goes to B, and the origin of movement is C to C, 

 and of both to both ; but from Β to C it travels by 

 going from Β to A as to a central origin, and from 

 A to C as from a central origin. Movement, hoAvever, 

 contrary to reason, sometimes takes place and some- 

 times does not take place in the organs as the result 

 of the same thoughts, the reason being that the 

 matter which is liable to be affected is sometimes 

 present and sometimes not present in the proper 

 quantity and quality. 



We have now dealt with the reasons for the parts 

 of each animal, the soul, and also sense-perception, 

 sleep, memory, and general movement. It remains 

 to deal ■with the generation of animals. 



are unnecessarj' in view of the following sentences and con- 

 tradictory in doctrine to them. 

 "" See figure on p. 473. 



479 



