THE SPECIES 245 



In this way it is possible to reduce to a form that can be 

 visuaHsed the series of recurrent changes in the species. 

 This form resembles a plant, the stem of which, by rhythmical 

 repetition, gives off shoots ; of these a great portion come to 

 naught, but the remainder unite again to form a new stem. 



The greater our powers of visualisation, the better able 

 shall we be to make this picture richer in detail and more 

 true to Nature. 



We can also think of this coming into being and then 

 dying away as though it took place cinematographically ; 

 then we participate in the rhythm, and so get the right im- 

 pression of the species as a rhythmical sequence of acts. 

 The process of shaping, which follows on plan, and the forms 

 it produces, which likewise operate to plan, mutually release 

 one another. 



Framework and action are always restricted to the in- 

 dividual organism, and only at one stage, that of sexual 

 union, is there an inter-adjustment that does not belong to 

 the plan of the individual, but to that of the species. 



What shows us clearly that here the species itself comes 

 in and determines the shaping is not the renewal through 

 offspring, but the mixing of the properties. 



The creation of new subjects from the rich material of 

 the genes affords the species the possibility of shaping itself 

 anew with each generation. Without this, there would 

 be eternal repetition ; and so new variations on the same 

 theme continually make their appearance. 



Were it not for the perpetually repeated union, the species 

 would break up into long, uniform chains of individuals ; 

 whereas, the union of all the chains in pairs continually 

 revives the unity of the chains considered collectively. 



Moreover the picture of the species enables us to visualise 

 how species live together and affect one another, and so we 

 get a glimpse into the living tissue of Nature ; this was 



y 



