202 Descriptiofi of the Plates. 



mandibles,, maxillae and labium receive their nerve supply, 

 we find that the entire ventral cord is made up of ten 

 ganglia^ the last of which may be taken as representing 

 two. This number is less by one than that of the Lepi- 

 dopterous larva^ and, on account of the large size of the 

 third thoracic ganglion, we may suppose that in the Cock- 

 roach, the ganglion homologous with the fifth post-oral 

 ganglion of the Caterpillar has become fused, if it was not 

 originally connate, with the posterior thoracic ganglion. 

 Thus the thoracic ganglia of the Orthopterous insect, which 

 remain always as distinct masses in this order as also in 

 the Coleoptera, will correspond, as to the elements out of 

 which they are composed, with the bilobular centrally per- 

 forated mass whence the three pairs of legs and the wings 

 are innervated in Lepidoptera. The six posteriorly placed 

 ganglia of the Orthoptera and of the Caterpillar will corre- 

 spond with each other ; and, allowing for the disappearance 

 in the butterfly of the sixth and seventh post-oral ganglia 

 of the larva, with the four posterior ganglia of the perfect 

 Lepidopterous insect. 

 0. ' Verticillate^ ovary of right side, consisting of eight egg- 

 tubes, connected by a suspensory ligament, which is made 

 up by the fusion of filaments given ofi" from their respective 

 apices, and prolonged up to an attachment in the dorsal 

 region of the thorax. The ovarian tubules are here figured 

 as opening into the convex end of a pear-shaped oviducal 

 infundibulum ; and this apical insertion has been supposed 

 by Leon Dufour and Fischer to constitute an important 

 difference between the ai-rangements of the female repro- 

 ductive apparatus, as existing in the Blattinae and in other 

 Orthoptera. The pyriform shape however of the oviducal 

 infundibula depends merely upon temporary distension ; 

 and when these receptacles are not in this condition, the 

 egg-tubes may be seen to have the same lateral insertion as 

 those of other Orthoptera; as, for example, the Forficula, 

 as figured by Fischer in his work, Orthoptera Europaea, 

 tab. i., fig. 4 ; or the Mantis Beliglosa figured by Leon 

 Dufour in his work, Kecherches Anatomiques et Physiolo- 

 giques sur les Orthopteres, les Hymenopteres et les Neurop- 



