ECOLOGY — INTERPRETATION OF ENVIRONMENT 385 



On October first I examined a large number of the horseweed 

 and goldenrod afield, which showed the scars where the crickets 

 had oviposited. The fact was developed that the eggs of this 

 species were always deposited on the sunny south exposure 

 of the main stem of the plants. This is obviously an advantage 

 in furnishing the necessary heat in hatching the eggs and aids 

 the delicate young when they first emerge. In Fig. 1 the 

 serial sub-figures represent the stems of the blackberry, horse- 

 weed, and goldenrod, all shorn of leaves to demonstrate the 

 scars or holes, as well as the eggs in position. I witnessed the 

 act of oviposition for the first time on the afternoon of September 

 twelfth, and thereafter observed it on a number of occasions. 

 In brief, the process is as follows: The female, coming to a 

 suitable spot on the stem, prepares it by first biting it with 

 her jaws, spending scarcely a minute in doing so. Then, 

 moving her ovipositor under her body at nearly a right angle, 

 she places the tip in this superficial abrasion in the stem and 

 immediately proceeds to drill a hole. The drilling is accom- 

 plished by rotating the ovipositor while keeping the end, which 

 is provided with a dentate rasp, firmly pressed against the 

 stem. The abdomen, which she turns from side to side, takes 

 an active part in this procedure, acting as upon a pivot, and 

 at times covering about forty degrees in these movements. 

 The ovipositor is soon passed through the tough external 

 covering, finally penetrating deeper and deeper into the pith. 

 In the beginning the course of the hole takes a right angle, 

 but as she proceeds its direction is changed, taking a curved 

 inclination backwards, as depicted in the plate photographic 

 illustration. Fig. d. 



When the female has bored into the pith as far as the 

 ovipositor can go, she then discharges the slightly curved 

 egg very slowly. Then, after withdrawing the organ, she 

 finishes the process by chewing the stem at the point of 

 puncture as she did in the beginning of the operation. The 

 anterior, whitish-tipped end of the egg usually lies within a milli- 

 meter of the opening. This is shown in the specimen of golden- 

 rod (Fig. \d) laid open for inspection. Some of the eggs here 

 show the whitish micropilar extremity quite clearly. I did 

 not see the female use the same hole for the deposition of more 



