162 MICROSCOPY FOR BEGINNERS. 



tacles will be destroyed by the least rough handling), 

 cover with thin glass, and finish as in the case of any 

 fluid mount." I have not found it necessary to use two 

 slips of glass. If a deep shellac cell that has been made 

 for some time and is perfectly dry and hard is used, the 

 Hydras may be placed in it and there cooked and al- 

 lowed to remain. "When cold, arrange the arms if neces- 

 sary, add a drop of weak glycerine and water, and ce- 

 ment the cover -glass with shellac. The Hydras thus 

 prepared can be kept indefinitely, and at any time 

 shown to admiring friends. 



Both the green and the brown species are abundant 

 duiing the summer among Anacharis and Lemna. 



