11. 7—11. 8 37 



sanguineous animal in which this takes place.-* Man, again, has 

 more sutures in his skull than any other animal,^^ and the male 

 more than the female.^^ The explanation is again to be found 

 in the greater size of the brain, which demands free ventilation, 

 proportionate to its bulk. For if the brain be either too fluid or 

 too solid, it will not perform its office, but in the one case will 

 freeze the body, and in the other will not cool it at all ; and 

 thus will cause disease, madness, and death. For the cardiac heat 

 and the centre of life is most delicate in its sympathies, and is 

 immediately sensitive to the slightest change or affection of the 

 blood on the outer surface of the brain.^' 



The fluids which are present in the animal body at the time 

 of birth have now nearly all been considered. Amongst those 

 that appear only at a later period are the residua of the food, 

 which include the deposits of the belly and also those of the 

 bladder. Besides these there is the semen and the milk, one or 

 the other of which makes its appearance in appropriate animals. 

 Of these fluids, the excremental residua of the food may be 

 suitably discussed by themselves, when we come to examine and 

 consider the subject of nutrition.-® Then will be the proper time 

 to explain in what animals they are found, and what are the 

 reasons for their presence. Similarly all questions concerning 

 the semen and the milk may be dealt with in the treatise on 

 generation,^^ for the former of these fluids is the very starting- 

 point of the generative process, and the latter has no other 

 ground of existence than generative purposes. 



(Ch. 8.j We have now to consider the remaining homogeneous 

 parts, and will begin with flesh, and with the substance that, in 

 animals that have no flesh, takes its place. The reason for so 

 beginning is that flesh forms the very basis of animals, and is the 

 essential constituent of their body. Its right to this precedence 

 can also be demonstrated logically. For an animal is by our 

 definition something that has sensibility, and chief of all that 

 has the primary sensibility, which is that of Touch ; ^ and it is 

 the flesh, or analogous substance, which is the organ of this 

 sense. And it is the organ, either in the same way as the eye 

 is the organ of sight, that is it constitutes the primary organ of 

 the sense ; or it is the organ and the medium through which 

 the object acts combined, that is it answers to the eye with some 

 or other transparent medium attached to it.^ Now in the case of 

 653b. 



