46 LEISURE-TIME STUDIES. 



of the little animal known as the Hydra, or " Common Fresh- 

 water Polype" (Fig. i). The examination of this common 

 denizen of our pools and ditches may convince the most 

 sceptical that the issues of scientific study are not only varied 

 and interesting, but that they also sometimes lead us to 

 contemplate phases of life and growth not very far removed 

 from some of the most important problems which can well 

 occupy the consideration of the human mind. 



FIG. i. Hydrae. (In both figures young hydrae are represented budding from 

 the side of the parent.) 



The hydra of the zoologist by no means recalls to mind, 

 as regards its form at any rate, the famous being of mythologi- 

 cal lore ; although, as will hereafter be noted, in certain of 

 its features, the modern hydra may bear comparison with its 

 mythical namesake. If we take some water from 



" The green mantle of the stagnant pool," 



which has become overgrown with lower plant-life and water- 

 weeds flourishing apace under the kindly influences of the 

 summer sun, and place this water along with a small quantity 

 of the weeds in a clear glass vessel exposed to the light, 

 we may be almost certain to find that in due time several 

 small bodies of greenish colour have attached themselves 

 to the sides of the vessel. These bodies will congregate 

 chiefly on the side of the vessel next the light; and, as 

 regards their size, the beings referred to are seen to be by 

 no means large. A length of about a quarter of an inch may 



