NO. 6 GRASSHOPPER ABDOMEN SNODGRASS 59 



the act of boring a hole in the upper edge of the topmost board of a 

 six-plank fence. " The abdomen," he says " was curved downward, 

 and the toothed f orcipate valves of the ovipositor used as pincers with 

 which small pieces of wood were broken off." Within a distance of 

 30 feet on the top boards of the same fence, which were perfectly 

 sound pine, he found 15 other holes, but none of them contained eggs, 

 the wood apparently being too hard for the proper completion of 

 the borings. Cavities made in stumps and logs, however, were found 

 to have eggs in the horizontal part of each. 



The oviposition habits of Chrysochraon dispar have been recorded 

 by Ramme (1927), who says that all nests found in the neighborhood 

 of Berlin except one were in stems of raspberry bushes, though other 

 observers report finding them in rotten poplar stumps and in broken 

 stems of Angelica sylvestris. Ramme studied the insects in cages, 

 where they were supplied with short pieces of raspberry stems stuck 

 into moist sand. A female about to oviposit, he says, crawls up a 

 stem ; reaching the cut top she examines the pith with her antennae, 

 and then climbs over the top and down the opposite side a short dis- 

 tance. As soon as the ovipositor touches the pith it begins digging into 

 the latter, and soon forms a hole in which the end of the abdomen dis- 

 appears (fig. 23 B) ; deeper and deeper it sinks until after a half 

 hour or an hour the cavity is completed (C). Woody as well as fresh 

 stems are accepted. When the boring is finished, the abdomen is 

 buried to the fourth or at least to the middle of the fifth segment (E). 

 The length of the abdomen beyond this point is ordinarily only i or 

 i| cm (D), but during the digging process it may be stretched to a 

 length of 4 cm. In cages Ramme found that the insects were unable 

 to penetrate the stems unless they had access to the cut tops of the 

 latter, from which he concludes that in nature they must use injured 

 or broken canes. In each nest 12 to 30 eggs are deposited, placed 

 obliquely one above the other. 



The action of the ovipositor in manipulating the eggs issuing from 

 the oviduct has not received as much attention from students of 

 acridian behavior as have the processes of digging and oviposition. 

 Judging from the anatomical relation of the gonopore to the egg guide 

 and the ovipositor (fig. 20 A), it is clear that an issuing egg must be 

 conducted by the egg guide posteriorly and upward between the bases 

 of the free parts of the ventral valvulae. The eggs are normally so 

 oriented in the oviduct that the anterior pole (the head end of the 

 future embryo) is anterior ; the protruding egg, therefore, has its pos- 

 terior pole directed posteriorly and upward. Riley (1878) says the 



