158 TOILERS IN THE SEA. 



sorbed, whilst the colony, as a whole, still maintains 

 its full vitality. In some species there seems to be a 

 sort of winter rest, when numbers of the polypes are 

 absorbed, but with returning spring, are again repro- 

 duced as plentifully as ever. 



The growth and extension of the colony, or poly- 

 pary, proceeds in a similar manner to the growth of 

 a plant, by the production of buds. Every colony 

 has originated from a single polype, and the plant- 

 like form has been acquired by a succession of buds. 

 " The Hydroid colony is enlarged by a purely vege- 

 tative process ; fresh polypites bud rapidly from the 

 prolific pulp, and in the larger and arborescent kinds, 

 branches and branchlets germinate, according to the 

 pattern of the species, from the zoophyte, as from the 

 tree. For the multiplication and diffusion of the 

 species, special zooids are set apart ; and to them is 

 allotted the reproductive function, as to the polype 

 that of nutrition. They correspond with the flower- 

 buds of the plant." l 



" Each wrought alone, yet all together wrought, 

 Unconscious, not unworthy, instruments, 

 By which a hand invisible was rearing 

 A new creation in the secret deep." 



Sexuality, in connexion with these zoophytes, has 

 not as yet been alluded to, because the fixed polypes, 



1 Hincks's " Hydroid Zoophytes," p. xx. 



