STALKED EGGS 



517 



or those laid in the water, as the eggs of dragon-flies, caddis-flies, 

 Chironomus (Fig. 484), etc., are enveloped by a jelly-like mass. 



The ootheca of the cockroach (Fig. 485) is a solid, dense case, which, 

 after being carried about by the mother, can be left without harm in 

 the crevices of the floors of houses. c 



The ootheca of Mantis (Fig. 486) is 

 formed by a large mass of frothy 

 matter, which hardens and is at- 

 tached to stems of plants. 



FIG. 485. Egg-capsule of Periplaneta 

 americana : a, side ; b, end view ; o, natural 



, , , 



size. After Howard and Marlatt, Bull. 4, 



s . Dept. Agr. 



On the Other hand, the female " walk- 



,.,.,,.,., ,. . N . 



mg-stick" (Diapheromera Jemoratum) Dlv Ent 



drops her eggs, says Riley, loosely upon 



the ground, from whatever height she may happen to be, and "one hears a 



constant pattering, not unlike drops of rain, that results from the abundant 



dropping of these eggs, which, in places, lay so thick among and under the 



dead leaves that they may be scraped up in great 



quantities." (Report for 1879.) 



The eggs of the lace-winged flies are sup- 

 ported on pedicels, above the reach of ovivorous 

 mites. 



The female Chrysopa usually lays between 40 and 50 

 eggs. In one case, we observed that 18 egg-stalks were 

 deposited, but there were only nine well-formed eggs in 

 the batch, and nine eggless stalks, some only half the 

 usual height, others with the knob of cement at the 

 end to which the egg is ordinarily fastened. The eggs 

 are evidently stuck on to the end of the pedicel after the 

 latter has been formed, as, in one instance, an egg was 

 glued to the stalk very much out of centre, the insect's 

 abdomen not having been aimed straight, so to speak, at 

 the mass of cement. 



The eggs of Rhodites are fixed to a long stalk thickened 

 at the end ; those of Inquilines and certain Chalcids 

 (Leucospis gigas, Fig. 489, A) are also stalked ; and the 

 use of this stalk in the eggs of Cynips (E) is thought 

 by Adler to be respiratory, while, also, he states that 

 the egg-cav- 

 ity commu- 

 nicates with 

 the egg- 

 stalk, so 

 that a part 

 of the egg- 



contents can pass into the latter, 



and this happens at the laying of 



each egg. The egg of certain ich- 



neumonS (Paniscus, Fig. 488) ends 



in a short Stalk, which is inserted FIG. 487. Eggs of Chrysopa, with larva and fly. 



FIG. 486. Egg -cap- 

 sules of Mantis Carolina. 

 After Riley. 



