128 



THE SEA SHORE 



feeds. This would undoubtedly be the case even if they were 

 capable of mechanical action only, but, in many instances at 

 least, they seem to be aided by the presence of some violent irri- 

 tant, judging from the rapidity with which the struggling prey 

 is paralysed when seized, especially in the case of some of the 



larger members of the 

 group. 



The simple forms re- 

 ferred to increase by a 

 process of budding, the 

 buds appearing first as 

 simple swellings on the 

 side of the parent crea- 

 ture, and afterwards de- 

 veloping a mouth and 

 tentacles, thus becoming 

 exactly like the adult 

 form. Clusters of eggs 

 also are developed in the 

 outer layer of the body- 

 wall, and these are set 

 free at intervals, and 

 produce new individuals. 

 These animals possess no 

 blood system of any kind, 

 and have no special organs 

 for respiration, but the 

 nutrient matter absorbed 

 from the body-cavity per- 

 meates the soft structures 

 of the flower-like body, 

 and the oxygen required 

 for respiratory purposes 

 is readily absorbed from 

 the surrounding water. 



The higher coslenterates differ in certain particulars from the 

 lower forms just referred to. Thus, they frequently have a large 

 number of tentacles around the mouth, often arranged in several 

 distinct whorls. They have also a stomach separate from the 

 general body-cavity, but communicating with the latter below; 

 and the body-cavity is divided into compartments by a number of 



FIG. 78. THE SQUIRREL'S-TAIL, SEA Fm 

 (Sertularia argentea), WITH A PORTION 



ENLARGED 



