250 THE AMERICAN MONTHLY [Aug. 



small jn'nii:iiieut pooLs, sluillow inlets in iliPshor(\s of 

 lakes, anil the places where tli(> trasli falls in the eddies 

 of streams. 



They are quite as easily reared. Commau wooilt-n kits 

 and pails half filled with water, with screen or netting 

 covers are entirely satisfactory. A number of nymphs, if 

 near one size, may safely be kept together (e.\ce[)ting 

 only a few notoriously cannibalistic Aeschinidas : e. g. 

 Anax Junius), and if not grown may he fed upon such 

 small insects as a net will gather in any pond. A good 

 square meal once a week will keep them thriving. The 

 water should be reasonably clean. Three things should 

 be carefully observed. (1) There must be a surface up 

 wliich they can climb to transform : if the sides of the 

 kit are too smooth put in some sticks; (2) there must be 

 room enough between the netting cover and the water 

 for complete expansion of their wings: (3) they must 

 remain out of doors where the sunshine will reach thtMu. 

 This last [)oint especially is essential to success. But 

 there is still an easier way to do it, and one which, when 

 a species is very common, will prove entirely satisfactory. 

 The several nymphal stages (excepting the youngest, not 

 likely to be collected) are very much alike. 1 am in the 

 habit of preserving the younger nymphs and putting into 

 my kits only those well grown, as shown by the len<ith 

 of the wing-cases, which should rcac-h the middle of the 

 abdomen. But if, when a species is becoming common, 

 one v/ill go to the edge of the water it frequents, at the 

 time of its emergence, one may iind nymphs craw ling 

 from the water, othci's ti'ansforn)ing, imagoes drying 

 their wings, and others ready to liy, and may thus obtain 

 in a tew minutes the material necessary for determining 

 nymph and imago. The time of emergence may he 

 determineil by noticing at what time jtale young imagoes 

 are seen taking then hrst llight, and then going out a 

 little earlier. The unfortunate thing about it is that 



