March, 1916.] CrAMPTON : OrIGIN OF WiNGS. 19 



pansions which are eventually to become wings, must do, in order to 

 develop an articulation with the tergum ! I have not examined these 

 ''pteriform" expansions of the Acarina, however, and would not at- 

 tempt to state whether or no they are homologous with the wings of 

 insects. 



15. The fact that paranoial expansions can become large enough 

 to act somewhat after the fashion of a parachute, or gliding planes, to 

 break the fall of the insect, is shown by the pronotal development of 

 the Mantid Chosradodis (Plate II, Fig. 9). The dried specimen will 

 " sail '' for a considerable distance, if dropped from a height, and I 

 imagine that the living insect could do the same. Tracheal gills of 

 such a size are unknown. 



16. In order to function as a gliding plane, the paranoial expan- 

 sions should be developed in insects which have a tendency to leap 

 into the air, otherwise the expansions would not have much of an 

 opportunity of functioning, unless the insect were to drop from a 

 height. 



Since the Mantids such as Rhombodcra, Chocradodis (Fig. 9, 

 Plate II), etc., have developed such large pronotal paranota, I have 

 asked Mr. A. N. Caudell (to whom I am indebted for the determina- 

 tion of the Mantid and Phasmid depicted in Figs. 9, 11, and 14, 

 Plate 11) whether the Mantids exhibit any tendency to leap, and 

 would quote the following from his reply. " I have seen our native 

 species leap a couple of inches, and Yersinia, a western species, can 

 leap half a foot. Anieles, from Portugal, is reported by Wood- 

 Mason as being able to leap nearly a foot straight upwards. In all 

 cases it is the nymphs that leap and in some cases the hind femora 

 are distinctly enlarged as in the saltatorial groups." 



It is thus evident that forms having large paranota may also ex- 

 hibit a tendency to leap, but I have been unable to find an instance 

 of nymphal Ephemerids (or forms with flat tracheal gills) exhibit- 

 ing a tendency to leap. 



17. It might be further remarked that the leaping tendency " crops 

 out" in the most diverse forms, such as the Apterygota (c. g., 

 Machilis, etc.), the Psyllids, Flea-beetles, etc., and may possibly indi- 

 cate an inherent tendency in the insect stem, which finds opportunity 

 for expression in certain forms, and would of course be especially 

 useful in those insects which have developed large paranota. 



