Vol. 1.] Woodworth. — Wing Veins of Insects. 119 



hard to determine the order of the development of these veins, 

 but it is possible that it is from the front backward. 



Both Redtenbacher and Brongniart have attempted to 

 homologize the veins of these insects, and agree in considering 

 the radiating veins comparable with the radiating veins in 

 grasshoppers. The posterior would thus be their vein IX as 

 well as the rays. It is very difficult to conceive the stages in 

 the migration of the vein IX out beyond the tip of the inde- 

 pendent, and, besides, the folding of this wing is fundamentally 

 different from the folding of the anal area of Orthoptera. 



ORTHOPTERA. 



The Orthoptera, omitting the two families just considered, 

 are, as far as differentiation is indicated by the venation, much 

 simpler than the preceding families. The Paleozoic ancestors 

 bore the same relation to the Paheoblattida^ that the modern 

 forms do to the Blattidae. We know that the venation is one 

 capable of extreme specialization, as is shown by the remark- 

 able stridulating organs in the males of Gryllidse and Locus- 

 tidae (see Fig. 25, showing the wing of the common cricket). 



The shape and function of the front wings are not such as to 

 favor the development of any new or more definite venation, 

 and the hind wings are taken up with the arrangements for 

 folding, which requires and maintains a monotonous repeti- 

 tion, instead of high specialization. There is great similarity 

 between the venation of the Blattida' and that of other Orthop- 

 tera, except that the Blattid venation is rather more definite 

 and complete. There are many examples of reduced venation 

 among the Orthoptera, but in no case is there reduction with 

 specialization, except it be for some other function than flight. 



The Phasmida? are mostly apterous, and when possessing 

 wings, these have been so reduced that only the more impor- 

 tant of the longitudinal veins remain. Under these conditions, 

 unless the wing is too much reduced, the characteristics of the 

 orthopterous venation are clearly seen, especially in the folded 

 area of the hind wing. 



The Mantida? possess the least differentiated wing in the 

 whole order, and the greatest number of longitudinal veins. 

 These are extremely variable, as in the Xeuroptera, and very 

 regularly placed. 



The Acridida> show something of a reduction in the number 



