THE MICROSCOPE. 



JUIvY, 1895. 



Number 31. 



New Series. 



The Trichodine Infusoria, a Parasite of the Fresh- 

 Water Hydra. 



[Translated from " Le Naturaliste."] 



By chrysanthemum. 



The fresh water hydra, the most simple of all polyps, 



lives in all ditches wherever running water bathes the 



lemna and other aquatic plants. To obtain them, it is 



sufficient to take a handful of the plants, press them 



between the fingers and collect in a glass vessel the wa- 

 ter which flows from them. 



The next day, one will be almost sure to see against 

 the transparent sides of the receiving glass some little 

 green and brown thread-like bodies, terminated by a 

 bundle of fine grasping filaments. These are the 

 hydra. 



