IOO ELEMENTS OF BIOLOGY. 



organism as the common sea-mat (Flustra), which is a com- 

 posite organism composed of a multitude of similar beings, 

 each of which inhabits a little chamber or cell ; the whole 

 forming a structure not unlike a sea-weed in appearance 

 (fig. 27). This colony is produced by gemmation from a 



Fig. 27. Flustra hispida, one of the Sea-mats, a Portion of the colony, natural 

 size ; b A fragment magnified, to show the cells in which the separate polypides 

 are contained. 



single primitive being (" polypide "), which throws out buds, 

 each of which repeats the process, apparently almost inde- 

 finitely. All the buds remain in contact and connected 

 with one another, but each is, nevertheless, a distinct and 

 independent being, capable of performing all the functions 

 of life. In this case, therefore, each one of the innumer- 

 able buds becomes an independent being, similar to, though 



