LAET^ OF WATEE-FLIES. 253 



the perfect Dragen-fly, it ceases to eat, and begins to grow 

 languid. It should now, if in captivity, be provided with 

 some means by which it may leave the water. A piece of 

 stick put slantingly in the gravel and sand at the bottom of 

 the tank, and rising above the surface of the water, wUl 

 answer the purpose very weU. The pupa wUl creep slowly up 

 this stick, and wiU remain at some little distance above the 

 water, clinging with its claws (given it for this special purpose) 

 to the under side of the stick, and will wait there its final 

 change. In due time the skin at the back of the thorax 

 splits ; through this split, after considerable effort, the head, 

 thorax, and legs of the Dragon-fly slowly emerge, and then 

 the creatui-e, apparently quite exhausted with its struggles, 

 hangs helplessly down, the remaining portion of its body 

 still being within the old skin. When it has thus rested 

 sufficiently, it gradually lifts itself iip until it can grasp with 

 its legs the forepart of its late covering, and with this pur- 

 chase it is able to draw from the pupal integument the 

 remainder of its abdomen. It has now, with the exception 

 of the wings, all the appearance of a perfect Dragon-fly. 

 Gradually, however, the wings expand until they are of the 

 full size, and after a little hardening and drying they are fit 

 for use. The development of the Dragon-fly from the pupa 

 is a most interesting sight. I shall never forget my delight 

 ajid astonishment when the first pupa I kept became a 

 Dragon-fly. The change was made at night. (I beheve these 

 changes generally do take place at night, for the Dragon-fly 

 is at this time of its life so helpless, that if it were not for 

 the darkness it would have 'Httle hope of escaping from its 

 numerous enemies.) In the morning when I looked at my 

 pupa I saw it, as I thought, in the same place that it had 

 been the evening before, but on lifting the cover of the 

 aquarium. I found clinging to it a magnificent Dragon-fly of 

 the species ^schna maculatissima. I could not quite under- 

 stand its presence at the moment, for to aU appearance there 

 was still the pupa. However, on a closer inspection, I dis- 

 covered that it was only the skin of the former object of my 

 cai-e, though it was exceedingly like the insect itself. The larvEe 



