156 THE EVOLUTION OF CONTINUITY 



believe, been separately derived from parallel aqueous types. 

 The Continuity exhibited by terrestrial Individuals has been 

 evolved in a watery environment, and minor special terrestrial 

 characters are terrestrial modifications within each form 

 of Continuity. 



In a rough way we might picture the process as having 

 been somewhat as follows : — 



A. From a primitive Discontinuously Multicellular stock, 



whose environment was aqueous, a certain number 

 of Individuals developed in Filamentous Continuity ; 

 the rest breeding true through succeeding ages, 

 and their further evolution being only that of 

 Discontinuously Multicellular Species. From time 

 to time the land would probably obtain " primi- 

 tive types " from the fixed Discontinuously 

 Multicellular class. Even on land, however, the 

 environment would be largely aqueous. 



B. At some period a certain number of Filamentous 



Individuals would develop with the multiplied 

 Continuity of the Discontinuously Zooidal Indi- 

 vidual, while the rest continued to breed true as 

 Filamentous Individuals, their further evolution 

 being that of species. Probably from these would 

 be obtained at a later date freshwater filamentous 

 types. 



C. The evolution of Continuity would then, still in an 



aqueous environment, pass on to the Continuously 

 Zooidal Individual type in a certain proportion, 

 while in another it would remain arrested to 

 preserve for us at the present day the free zooid ; 

 that of Hydra being a modern species. It is 

 most unlikely that any primitive terrestrial Discon- 

 tinuously Zooidal Individual was ever derived 

 from an aqueous type. 



D. Still in oceanic environment, the primitive Contin- 



uously Zooidal form would then pass on into the 

 Discontinuously Megazooidal, and also continue to 

 breed Individuals whose Continuity did not change 

 to a higher form ; and from these, at varying 

 periods, we believe that the original types of the 



