50 THE HISTOEY OF ANIMALS. [B III. 



and not teeth in both jaws have cotyledons in the pregnant 

 uterus, and some of those also with teeth in both jaws, as the 

 hare, the mouse, and the bat. But other viviparous animals 

 with teeth in both jaws, and with feet, have a smooth uterus. 

 The embryo is not united to the cotyledon, but to the 

 womb. This is the manner of the internal and external 

 heterogeneous parts of animals. 



CHAPTEE II. 



1. Or the homogeneous parts of animals, the blood is com- 

 mon to sanguineous animals ; and so is the part in which it 

 is contained, which is called a vein ; analogous to these, in 

 exsanguineous animals are the serum and the fibre. That 

 which especially constitutes the body is flesh or its analogue : 

 the bone and its analogue ; the spine and the cartilage. 

 Next to this we place the skin, membranes, sinews, hair, 

 nails, and their analogue ; after these, adeps, fat, and excre- 

 mentitious matters ; then are faeces, phlegm, and bile, both 

 the yellow and the black. 



2. But inasmuch as the blood and the veins seem to 

 occupy the chief place, we will first of all speak of these, 

 both for other reasons, and because former writers do not 

 appear to have described them rightly. The difficulty of 

 understanding them is the reason of their errors, for in 

 dead animals, the nature of the principal veins is obscure, 

 for they collapse as soon as the blood has escaped, and it 

 pours out of them as from a vessel. No part of the body, 

 except the veins, contains any blood, except the heart, which 

 has a little ; but it is all in the veins. In living creatures 

 their nature cannot be distinguished, for they are internal, 

 and out of sight ; so that those who consider them only in 

 dead and dissected animals, cannot see their principal ori- 

 gins. But some, by the examination of emaciated persons, 

 have distinguished the origin of the veins, from the appear- 

 ance of those which are external. 



3. For Syennesis, 1 a Cyprian physician, speaks thus : 

 " The larger veins are thus constituted. From the navel 

 around the loins, through the back to the lungs, under the 

 breasts ; that from the right to the left, and that from the 



1 Syennesis, a physician of Cyprus. Very little is known of him j 

 b must have lived in or before the fourth century B.C. 



