THE DISCONTINUOUSLY ZOOIDAL 75 



return to this in a later chapter, we shall not dwell further 

 on it for the present. 



The question of space also prevents us from doing more 

 than suggesting that the progressive diminution of the 

 length of lines of cell-descent in the Discontinuously Multi- 

 cellular Individual should find expression in cycles like that 

 of Hydra's (see page 47). One aspect of this is suggested 

 in Fig. 17. 



We may close this chapter by recapitulating our theory 

 of Continuity's evolution up to the Individual type just 

 considered. 



Our first Individual type was the Discontinuously Multi- 

 cellular, and might be represented as 



oooooo 

 oooooo 

 oooooo 



Our second type was the Filamentous, and exhibited the 

 simplest form of Serial continuity, as in the next diagram : — 



(XOOCKXXXXDOOOOCXXXX^COOCXXXJCO 



In the type last considered the serial continuity of the fila- 

 ment is as it were multiplied into the Lateral continuity 

 of the independent zooid's tissues, so that the preceding 

 diagram becomes 



Thus we have our first exhibition of the alternation of 

 Serial with Lateral Continuity in the evolution of living 

 Individual growth-types. But it must not be supposed 

 that Evolution has been through any existing Individuals 

 manifesting the above forms of Continuity, for all these 

 Individuals are at the most advanced points of " species " 

 side-paths ; what is to be understood is that the main road of 



