PROGRESSION OF ANIMALS, vii. 



divided into several parts, and can no longer partake 

 of the motion from place to place whereby it moved 

 while it was still continuous and undivided. On the 

 other hand, some of the bloodless animals and poly- 

 pods can, when they are divided, live in each of 

 these parts for a considerable time and move with 

 the same motion as before they were divided, the so- 

 called scolopendi'ae,''for example, and other elongated 

 insects ; for the hinder part of all these continues to 

 progress in the same direction as the fore-part. The 

 reason why they live when they are divided is that 

 each of them consists as it were of a continuous body 

 made up of many animals. And the reason why they 

 are of this kind is clear from what has been said above. 

 Animals which are constituted most in accordance 

 with nature naturally move by means of two or four 

 points, and likewdse also those among the red-blooded 

 animals which are footless ; for they too move at four 

 points and so effect locomotion. For they progress 

 by means of two bends ; for in each of their bends 

 there is a right and a left, a front and a back in 

 their breadth — a front point on the right and another 

 on the left in the part towards the head, and the two 

 hinder points in the part towards the tail. They 

 appear to move at two points only, namely, the points 

 of contact with the ground in front and behind. The 

 reason for this is that they are narrow in breadth ; 

 for in these animals too, as in the quadrupeds, the 

 right leads the way and sets up a corresponding move- 

 ment behind. The reason of their bendings is their 

 length ; for just as tall men walk with their backs 

 hollowed ^ and, while their right shoulder leads the 



* XopSos is the opposite of κυψό^, hunchbacked (Hippocr. 

 Fract. 763). 



503 



