10 ANIMAL INDIVIDUALITY [OH. 



for the good of which that action is performed. From 

 the latter we can deduce another attribute of in- 

 dividuality its heterogeneity ; from that very unity 

 of the whole we can postulate diversity of its parts. 

 This sounds paradoxical, but in reality it can be easily 

 shown that nothing homogeneous can be an indi- 

 vidual. 



Suppose (as is highly probable) that the earliest 

 forms of life were homogeneous in chemical compo- 

 sition. If so, even were they compelled by the 

 nature of things (see Chap. II) to exist as separate 

 masses of defined shape and size, even though, by 

 reason of their complicated atomic structure, they 

 could carry on all the diverse functions necessary for 

 their continued existence with their one chemical 

 substance, they would then not be individuals. There 

 is no unity residing in such masses they are the 

 merest aggregates ; whether you divided one into two 

 or twenty or a hundred pieces it would still go on 

 working in the same way, without a break 1 , whereas 

 if you divide a man into two by cutting off his hand, 

 the working of the main part the man is rendered 

 less effective, and that of the lesser part the hand 



1 That is, of course, supposing the external world and the 

 properties of matter allowed it to exist at all when in such small 

 masses : e.g. Lillie has proved that there is a minimum size (deter- 

 mined no doubt chiefly by surface-tension) below which pieces of 

 Stentor (a ciliated Infusorium) cannot regenerate. See p. 47. 



