140 



INSECT LIFE. 



io. Place the pinned specimens in your collection 

 with the Hemiptera under a copy of the following 



label : 



Family CORISID^E (Co-ris'i-dae). 



The Water-boatmen. 



THE NYMPHS OF DAMSEL-FLIES (Field Work\- 

 The nymphs of damsel-flies are truly aquatic, having 

 gill-like organs which enable them to live in water 



without coming to the surface from 

 time to time for a supply of air. 

 They may be found in those ponds 

 or streams about which the adults 

 fly, and are most abundant among 

 the stems of submerged plants. Fig. 

 113 will enable you to recognize 

 these insects when found. 



Collectspecimens of these nymphs 

 1 and place them in aquaria for study. 

 THE HABITS AND STRUCTURE 

 OF THE NYMPHS OF DAMSEL-FLIES 

 (School Work}- -The nymphs of dam- 

 sel-flies are easily reared in aquaria 

 of in which the water is kept pure by 

 growing plants. Frequently tiny 

 ones will appear in such aquaria from eggs that were 

 in the stems of the plants when they were collected. 

 In such cases it is easy to watch the entire life 

 history of the insect after it leaves the egg. 



We will not outline such a study, for the pupil 

 who has made the observations on pond life already 

 indicated will be able to direct his own studies; and 

 independent original observations are much more 



FlG - 



