GRASSHOPPERS IN GENERAL. 21 



tough and resistant, but, on exposure to the 



elements, becomes friable and easily separable. 



Upon the removal of this external covering, 



the clear, bright yellow of the underlying egg 



substance is seen. 



The structureless vitelline membrane forms 



an efficient protection for the enclosed egg. 

 FiG4 It withstands drying, and is broken only by 



the application of considerable pressure. Im- 

 mediately beneath it is a layer of protoplasmic material, the real liv- 

 ing matter of the egg, and within this a considerable quantity of 

 nutritive material, the yolk. 



My observations upon these eggs, manner of placing in the ground 

 and the actions of the female during the time of oviposition are here- 

 with given. A female in quest of a suitable position for placing the 

 eggs generally moves slowly about for some time testing the ground 

 over which she passes. During this time the tip of the abdomen is 

 turned downward and, stopping momentarily, the ovipositors (plate 

 ii ) are applied to the ground. I observed one female spending thirty 

 minutes in this way ; a crevice in the soil being selected and worked 

 upon for a time, then abandoned for solid ground. Some, however, 

 begin digging and complete the work where the first attempt is made. 

 Small elevated spots on the surface appear to be much chosen. Fre- 

 quently these little hillocks were not noticeable until marked by a 

 locust digging into the crest. From plate in, figures g, g, g", it is 

 evident that there has been a consensus of opinion in these cases con- 

 cerning the suitability of the place for oviposition. Sandy soil, when 

 present, seems preferable. 



That field observations might be corroborated in the laboratory, I 

 brought home 130 of the yellow locusts, more than 100 of these being 

 females, for study in the vivarium. 



In one cage sixty were placed, and blue-grass sod, clover sod, sand 

 and dirt mixed, and pure sand; each class of soil occupied a certain part 

 of the floor, the whole floor being well packed by sprinkling. In this 

 cage, the pure sand was chosen by all except eight, which placed their 

 eggs in the sand and dirt mixed. Refuse from the vegetation given 

 them for food seemed in no way to intefere with their work. I saw 

 three of them hid away in this trash busily engaged in ovipositing. 



A suitable place chosen, the locust forces a hole in the ground by 

 means of the two pairs of horny-tipped ovipositors at the end of the 

 abdomen. These are opened and closed and the full weight of the 

 body is brought to bear on them. In this way a receptacle is made, 

 often in extremely firm ground, for the eggs. 



