86 iii. 12 — iii. 14. , 



of oviparous quadrupeds and of fishes is, 'as a rule, of a pale 

 yellow,* and there are even some in which its colour is utterly- 

 foul,-^ so as to match the foul composition of their bodies. Such, 

 for instance, is the case in the toad, the tortoise, and otlier similar 

 animals. 



The spleen, again, varies in different animals. For in those 

 that have horns and cloven hoofs, such as the goat, the sheep, 

 and the like, it is of a rounded form ;^ excepting when increased 

 growth and size has caused some part of it to be lengthened out, 

 as has happened in the case of the ox."" In all polydactylous 

 animals on the other hand it is elongated. Such for instance, is 

 the case in the pig,^ in man, and in the dog. While in animals 

 with • solid hoofs it is of a form intermediate to these two, being' 

 broad in one part, narrow in another. Such for example is its 

 shape in the horse, the mule, and the ass. 



(Ch. 13.^ The viscera differ from the flesh not only in the turgid 

 aspect of their substance, but also in position ; for they lie within 

 the body, whereas the flesh is placed on the outside. The expla- 

 nation of this is that these parts partake of the character of blood- 

 vessels, and that while the former exist for the sake of the vessels, 

 the latter cannot exist without them.^ 



(Ch. i/!if.) Below the mid-line of the body lies the stomach, 

 placed at the end of the oesophagus, when there is one, and in 

 immediate contiguity with the mouth, when the CESophagus is 

 wanting.^ Continuous with this stomach is what is called the 

 gut. These parts are present in all animals, for reasons that are 

 self-evident. For it is a matter of necessity that an animal shall 

 receive the incoming food ; and necessary also that it shall dis- 

 charge the same when its goodness is exhausted. This residual 

 matter, again, must not occupy the same place as the yet uncon- 

 cocted nutriment. For as the ingress of food and the discharge 

 of the residue occur at distinct periods, so also must they 

 necessarily occur in distinct places. TJius there must be one 

 receptacle for the ingoing food and another for the" useless 

 residue, and between these, therefore, a part in which the 

 change from one condition to the other may be effected. These 

 however are matters which will be more suitably set forth, when 

 we come to deal with Development and Nutrition. 



We must now consider the variations presented by the stomach 

 and its subsidiary parts. For neither in size nor in shape are 

 674a. 



