NO. 6 



GRASSHOPPER ABDOMEN SNODC.RASS 



53 



(fig. 2.2 h), but they are never apparent as specific structures. The 

 coxopodites of the ninth segment, on the other hand, are evidently 

 contained in the posterolateral parts of the apparent ninth sternum 

 of the very young nymph (A, IXS) ; later they appear as distinct 

 membranous lateral areas (C, IXCxpd) from which the third valvulae 

 (jF/) project as direct continuations, and from which the small sec- 

 ond valvulae {2VI) arise medially as endite lobes. The coxopodite 

 areas remain membranous in the adult. The true sternal region of 



Stn aiv 

 Cxpd^ _ ^/ ^ ^Cxpd ly,j\ 



Papt 



A^l 3Vi B ""'' ^ "^ D 



Fig. 22. — Development of the ovipositor of Acrididae. 



A, ventral view of end of abdomen of first instar nymph of Mclanophis, show- 

 ing first valvulae as small lobes arising between eighth and ninth sterna, and 

 third valvulae as processes of ninth sternal plate. B, later stage of same, lateral 

 view. C, same as last, ventral view, showing intermediate second valvulae. 

 D, valvulae of ninth segment seen as processes of the coxopodite areas, in which 

 valvifers are not formed in Acrididae. 



the ninth segment becomes reduced to a narrow median band between 

 the bases of the valvulae, which includes the areas (D, aiv, piv) 

 in which finally will be formed the intervalvular sclerites. 



From the above it seems clear that the peculiar f eature_ of the acri- 

 did ovipositor is the lack of valvifer sclerites, a conclusion which 

 might be deduced also from the absence of dorsal muscles correspond- 

 ing with the tergovalvifer muscles of other insects. A different view 

 of the matter, however, has been taken by Nel (1929), who contends 

 that the manner and place of origin of the two first-formed pairs of 

 ovipositor processes leave no doubt that the latter are serially ho- 



