PSE UDONE UR OP TEH A . 



149 



'too 1 - 



brackish water, with her abdomen submerged in part, and there attaching a cluster of 

 eggs. I feel pretty sure that L. auripennis does not always deposit the whole of her 

 eggs at one time, as I have seen her attach a cluster of not more than a dozen small 

 yellow eggs. There must be more than one hundred eggs in one of the large bunches. 

 I have observed females of Perithemis domitia on a sunny day late in July hoverin<>- 

 over the surface of a pond, dipping the abdomen (the body being in a perpendicular 

 attitude with the wings in rapid motion) lightly into the water, which just covered a 

 piece of floating cow-dung, and then fly off to return again and repeat the operation. 

 Several dragon-flies were coursing over the small pond, and we are inclined to think 

 that two or more dragon-flies pushed their eggs into this same mass of ordure. The 

 dipping motion was the work of an instant ; whether one alone or a packet of eggs 

 were deposited at a single dip of the hind-body I could not say, but from the arrange- 

 ment of the eggs they were probably deposited singly." The eggs of a smaller and 

 more common dragon-fly (Diplax) were found 

 by Professor Hyatt early in July (the 2d) at- 

 tached to the leaves of a submerged sedge. 

 They were dispersed through a long ropy gela- 

 tinous mass, about a quarter of an inch thick, 

 which twined about the leaves of the grass. 

 These eggs must have been laid for a week 

 or more, as on the 16th of July large numbers 

 had already hatched. They continued to hatch 

 while in glass jars till the first week of Septem- 

 ber, those eggs situated in the middle of the 

 gelatinous mass seeming to hatch last ; in this 

 way a succession of young dragon-flies were 

 disclosed through the summer. The eggs are 

 oval-cylindrical. The egg-laying habits of the 

 small Agrions and their allies are most singular. 

 These creatures of the air and sunlight, when 

 impelled to deposit their eggs, deliberately 

 enter the water, walk down some submerged 

 stem, and with their ovipositor cut gashes in 

 the stalk into which they push their eggs. 



The larva? of most dragon-flies are rather 

 stout-bodied, sometimes broad and flat, espe- 

 cially the hind-body, and are very active in 

 their habits, constantly foraging after food, 

 creeping about over the bottom, or making 

 their way through thickets of submerged 

 aquatic plants. They can also propel themselves forwards for 

 inches by a curious method. The end of the intestine 

 wards of the water, which fills up the dilated rectum ; the walls of the rectum are 

 provided with many small air-tubes, by which the air is extracted from the water 

 and distributed throughout the body. After all the air is extracted from the water 

 the walls of the passage violently contract and force the water out in a powerful 

 stream as if from a syringe, and thus the insect is sent headlong through the water. 

 In the larva; of the smaller genera of the family, such as Agrion, etc., respiration 



FIG. 216. Larva of dragon-fly, just hatched. 

 d, heart, n, nervous cord, t, trachea. 



a distance of several 

 opens for the passage in- 



