272 



PSrCHE. 



[August — December 1SS9. 



Udeopsylla the males are very generally 

 distinguished by the larger and more 

 numerous spines on the lower margin 

 of the posterior femora. 



15. '"That the male leads and the 

 female follows in the evolution of new 

 races." 



Little remains to be said on this point 

 since nearly all that has gone before 

 shows already that in orthoptera male 

 characters lead in the recognition if not 

 in the evolution of new species. No 

 student of orthoptera will question the 

 statement that were it not for the varia- 

 tion of the cerci and the last ventral 

 segments of the males of Melanoplus 

 and Pezotettix it would not Se possible 

 to recognize nearly so many species in 

 these genera as are now known to exist. 

 It is also indisputal:>le that in Mclatwphcs 

 especially in several instances, it is 

 practical! V impossible to distinguish 

 with certainty between the females of 

 closely allied species. Examples are 

 not wanting of cases in which the males 

 ditier so greatly from the females, that 

 they have been placed wdien first de- 

 scribed in different genera. The male 

 of CJiloealtis conspersa Harr., differs so 

 much from the female that Mr. Scudder 

 in his ignorance of their relationship was 



quite justified in describing the male 

 as Stenobothrus tne/anopleurus. The 

 males of Syrbitla admirabilis Uhler 

 are of two forms ; the green one, which 

 is very rare, resembles the female in 

 coloration but differs in structural 

 characters, and especially in the clavate 

 antennae. The dark form, in addition 

 to the structural features which are ver\- 

 similar to those of the green form, is so 

 very difi'erent in coloring that it was for 

 a long time widely separated from the 

 female, and as genera are now made, the 

 sexes may be considered generically dis- 

 tinct. 



It will be seen that orthoptera 

 furnish strong, if not striking, corrobora- 

 tive evitlence of the truth of Mr. Brooks's 

 theory of heredity. While I do not 

 pi"etend, in this hasty review, to have 

 exhausted the illustrations that might be 

 fvn-nished by the species and families 

 represented in the United States I have 

 not found any controvertive evidence 

 except the considerable variation in the 

 length and shape of the ovipositor of 

 Xiphidiitm^ that of the closely allied 

 genus OrcJiclhnum being quite constant, 

 and the less marked variation in the 

 length of the same organ in Conoccpha. 

 his, Thyreonotus and Grvlliis. 



