COMPOSITION OF COLONY. 455 



In the course of our examination, especially if a 

 little dissection be employed,, we find that it is not a 

 single animal that lies before us, but a multitude of 

 beings, all bound together by common and vital ties. 

 Each star is found to be a family ; each group of stars 

 a community. Communities are linked together in 

 systems, and systems are combined into masses. 

 Every member of the commonwealth has its own 

 peculiar duties, but shares also in operations which 

 relate to the existence and well-being of the entire 

 organism. There is great diversity of arrangement 

 observable in different races, all of which, close in- 

 spection shows to be extremely beautiful ; indeed, 

 few creatures among the lower forms of animal life 

 exhibit such exquisite and kaleidoscopic patterns as 

 those which we see displayed in the surfaces of these 

 jelly-like substances. The individual animals com- 

 posing one of these elegant colonies (PI. VIII. fig. 2, a), 

 notwithstanding their minute size, are found, when 

 examined anatomically, to be constructed in every 

 respect upon the same plan as the Simple Ascidians 

 described in the last chapter; each member of the 

 community, however extensive, being complete in 

 itself, although organically conjoined with its neigh- 

 bours by means of the common fleshy substance in 

 which they are all imbedded ; but this is only during 

 the adult period of their existence, for they, like the 

 preceding, undergo a metamorphosis prior to their 

 final fixation, which, to the aquariist, will afford 

 abundant scope for exercising his talents of observa- 

 tion. We will try to lay before him. what is at pre- 

 sent known concerning this portion of their history. 



