THE FLORAL WORLD AND GARDEN GUIDE. 303 



fixed itself by its sucker, it elongates its body, and spreads out its 

 arms in different directions, and when any wandering animal im- 

 pinges upon its arms, it is immediately arrested, and becomes mo- 

 tionless as if benumbed. And this, be it observed, is the more 

 remarkable, as it was not struck, but only touched, by the arms of 

 the Hydra as it was moving along in its own course. What power 

 the arms of the Hydra possess it is difficult to conjecture ; its 

 effects are like the sudden shock of electricity, for the animal, 

 under the influence of its potent shock, seems motionless and sinks 

 to die, or only after the lapse of some time recovers itself. When 

 the prey is thus become motionless, the Hydra slowly contracts its 

 arms around it, and gradually brings it to its mouth, and then en- 

 gulphs it in its capacious stomach. 



We may now observe what takes place upon the prey that is 

 swallowed into the distended stomach, for the body of the Hydra is 

 so thin and pellucid that, with the aid of magnifying glasses, we 

 are enabled to see the process ; nor have we to wait long, for soon 

 the swallowed animal loses its form, and becomes a confused mass ; 

 all its digeetible parts are then soon dissolved, and that which is 

 hard and indigestible, such as its shell, etc., is at length expelled 

 from the stomach through the opening by which it was admitted. 

 It occurred to Trembley (whose observations upon the Hydra are 

 the earliest and best upon record), that from the transparency of 

 the body of the Hydra he might ascertain the manner in which the 

 digested particles became appropriated to the sustenance of the 

 animal. To accomplish this, he fed the Hydra with the red larva of 

 some insect, and the result was, that it is through the medium of 

 the green granules floating in the semi-fluid transparent substance 

 of the Hvdra that the diffusion of the coloured particles was accom- 

 plished, and that the granules themselves became of the same colour 

 as the food, but that the gelatinous matter remained colourless. 



Trembley also remarked that the digestive power of the Hydra 

 had no influence on the tissues of its own body ; for he observed 

 that some of the species occasionally swallowed their own arms 

 together with their food, and these remained during the process of 

 the digestion of the animal which it had swallowed, without being 

 injured. On one occasion, the same author says that he observed 

 the extraordinary occurrence of two Hydra having hold of the same 

 prey, and that they contended for the possession of it, and that the 

 conquest was terminated by one swallowing the object of dispute, 

 and also its rival. But imagine what was the observer's astonish- 

 ment when he afterwards saw the swallowed Hydra, together with 

 the refuse of the digested meal, ejected, and that the Hydra, after 

 its capture and imprisonment in such a perilous place, was apparently 

 none the woroe ! 



Wonderful as these facts are regarding the nutriment of the 

 Hydra, they are not more so than the manner in which the species 

 are multiplied, or ita lost parts restored. Trembley cut a body 

 transversely into two, and others into several portions, and he found 

 that each part, in process of time, became furnished with arms at 

 one extremity, and with a sucker at the other, and acquired all the 



October. 



