hear big on the orirjin of Insects. 

 Fiir. 9. 



167 



rig. 9. ' Blatta,' sp. Appendages of the ninth abdominal somite, or 

 posterior gonapophyses, of the female, drawn from the same 

 specimen as fig. 7, and viewed from the dorsal or upper side, so 

 as to show the triangular endopodites (5) answering to the pos- 

 terior elements of the ovipositor in Machilis and Lepisma ; 

 a, the exopodites, which are as firmly chitinized and as deeply 

 coloured as, hut relatively even larger than, the obviously homo- 

 logous ' styles ' of many male Blattidm (fig. 4, representing 

 the sternum, with appendages of the ninth abdominal sternum 

 in the male of the same or an allied species) ; p, the coalesced 

 basal joints (protopodite) of the biramous limb of one side : 

 the part of this that carries the exopodite is produced much as 

 in Machilis (fig. 8), but instead of meeting its fellow of the 

 ojiposite side in the middle line, so as to conceal from their 

 origin the endopodites that are attached to its own and to its 

 fellow's base, meets its fellow only at the inner extremity, where 

 it is expanded and strongly spined, so as to resemble, and, pei'- 

 haps, to serve as, a forceps ; the dotted lines represent the inner 

 margins of these produced exopoditic portions of the protopo- 

 dites as seen from the ventral or under side, in which view the 

 endopodites can only be seen meeting in a straight median suture 

 in the triangular hiatus bounded by the margins here shown in 

 dotted outline. 



In a much earlier stage than the one here depicted, the exopo- 

 dites are represented by minute buds only, which increase with 

 each successive eedysis. In many Blattidce which are much 

 more modified than this, as, for instance, in Paneathia Javanica, 

 no vestiges of exopodites appear to be present i". either sex, at any 

 stage, on cither the eighth or the ninth abdominal sternum 

 The sternum is not shown in this figure. 



