PARTS OF ANIMALS, IV. iv.-v. 



special name for it in the others.) Now there must 

 be some passage or passages (as it might be roots) 

 through which this nutriment shall pass from the 

 stomach to the blood-vessels. The roots of plants 

 are of course in the ground, because that is the 

 source from which plants get their nutriment. For 

 an animal, the stomach and the intestines correspond 

 to the ground, the place from which the nutriment 

 has to be derived. And the Mesentery exists to 

 contain these vessels, corresponding to roots ; they 

 pass through the inside of it. This completes my 

 account of its Final Cause. As for the means by 

 which the nutriment is taken up, and the way in 

 which that portion of the ultimate nutriment which 

 is distributed into the blood-vessels reaches all the 

 parts of the body through them, these points will 

 be dealt with in the treatises on the Generation of 

 Animals and on Nutrition. 



I have now described the blooded animals as far 

 as concerns the parts that have been dealt with, and 

 also the causes that are responsible. It remains, 

 and would follow after this, to speak of the organs 

 of generation, by which male and female are dis- 

 tinguished. But as we shall have to deal with 

 generation itself, it is more appropriate to speak of 

 these organs in our consideration of that subject. 



V. The animals called Cephalopods and Crustacea internal 

 are very different from the blooded ones. First of all, bloSless 

 they have no visceral structure at all. This is true animals. 

 of all the bloodless creatures, in which are included 

 beside Cephalopods and Crustacea two other groups, 

 the Testacea and the Insects. This is because none 

 of them has blood, which is the material out of which 



L 315 



