102 HOURS WITH NATURE, 



offence and defence. Although not as easily seen as 

 the tentacles and spines, yet if one of these animals 

 be carefully examined, a mouth will be sure to be found 

 through which food is ingested. The simplest form of 

 a stinging Zoophyte is seen in a 



"HYDRA, an animal that can only be properly examin- 

 ed under a microscope. But we need not despair of 

 seeing what it is like, as it is here represented in the 

 form of an enlarged drawing from which it will appear 

 that it is an animal having the form of a simple tube, 

 closed and often attached at one end, and provided at 

 the other with a mouth surrounded by tentacles. The 

 hollow of the tube forms the gastric cavity or stomach. 



"There are other and more complicated forms of 

 stinging Zoophytes, as a glance at these cases- will show. 

 Here is for instance a tree-like colony of animals. 1C 

 we were to trace the life -history of this colonial form, 

 we would probably find that some single individual of the 

 Zoophyte class budded and branched again and again ; 

 and that the resulting offspring instead of separating 

 themselves to live individual lives all remained united 

 together and to the parent, to form this tree-like colony. 

 As, however, it would be impossible, within the limited 

 time at our disposal, to study in detail all the various forms 

 of stinging Zoophytes and the interesting gradations of 

 their structural peculiarities, we must for the present, 

 content ourselves with simply inspecting our old friends 

 the* Medusa and the Corals, as instances of further ad 



