24 ANIMAL INDIVIDUALITY [CH. 



Now each of these three forms that thus cyclically 

 recur is obviously an individual in the sense defined 

 by us: they are wholes with diverse parts, whose 

 working tends to their own continuance, even though 

 this continuance is limited. But besides this there 

 is the cycle itself to be reckoned with : it too is a 

 definite something, a whole, it too is composed of 

 diverse parts, sporocyst, redia, fluke, it too works 

 in such a way that it continues (and continues in- 

 definitely). What right have we to deny it an 

 individuality as real as those possessed by any of 

 its parts ? True, those parts are separated in space ; 

 but the ant-colony (p. 142) shows that this is no bar 

 to individuality. The real point is this : the exist- 

 ence of the sporocyst and the redia is of no direct 

 advantage to the individual fluke : it would grow and 

 lay eggs just as happily if all the host-snails, and with 

 them all sporocysts and rediae, present and to come, 

 were exterminated. It is however of advantage to 

 something, and that something can only be the race 

 of liver-flukes, the kind of protoplasm which by its 

 diflerence from other kinds has earned a special 

 name Distomum hepaticum. 



That is an extreme case ; the two kinds of 

 individuality may often be inextricably interwoven. 

 What is of advantage to one is usually of advantage 

 to the other, so that, by an over- emphasis of the 

 species-individuality of which we are the parts, it 



