1890-91.] A " Coionial" Herbariiiin specimen. 475 



Heart and blood-vessels are absent, respiration being effected 

 by means of finely ciliated tentacles, borne either on a circular 

 or crescentic apparatus — the lophophore. The ciliary action 

 serves to drive food particles into the mouth, whicli is placed 

 in the centre of the lophophore, and there are special muscles 

 for pulling this organ within the protective cell. In some of 

 the group certain zooids become wonderfully metamorphosed, 

 so as to resemble the beaks of birds, which grasp small worms 

 and the like, and hold them till they decompose, and their re- 

 mains are swept into the mouths of the zooids. In others, 

 the metamorphosis results in the formation of long, very active 

 whips, which are understood to serve a similar purpose with 

 the beaks. The reproductive elements are developed inter- 

 nally, and when mature pass into the body-cavity, where 

 fertilisation takes place. The larva, having undergone segmen- 

 tation, passes out in a ciliated condition, to live for a time a 

 free and roving life. By-and-by it settles down, buds, and 

 forms the network described. A small portion of another 

 species was found on the alga. In this the cells were oval, 

 hyaline, and connected together like a chain. 



We have thus seen that, instead of having one plant on the 

 sheet, as is ordinarily the case, we have had ten rej^re- 

 sentatives of the plant kingdom, and, besides, seven of the 

 animal kingdom. The former are members of two great 

 families, the latter members of five. Think of the history and 

 daily doings of that colony : seventeen species struggling for 

 existence in less than two cubic inches of sea ! Eeciprocity 

 is at work, the plant members agreeing to exchange the 

 necessaries of life with the animal members. Think, too, of 

 the rising generation setting out to occupy new regions. All 

 are moving — a few by currents, the most by apparatus of 

 their own. What a stir there must have been sometimes 

 around this quiescent Delesseria — floating tetraspores, carpo- 

 spores, auxospores, gemmules, and frustules, mingling with the 

 dashing swarmspores, zoospores, free vorticellte, sponge-larvte, 

 medusa-buds, and young polyzoans, the commotion being 

 increased by the currents caused by the sponges, bell-animal- 

 cules, and zoophytes ! And, after all, these form only a 

 fraction of the crowd that would sometimes be there, as all 

 know who have tried to identify the organisms got by dipping 



