658 C. E. McCLUNG 



The conditions in Stenobothrus have been reported with much 

 uniformity by Davis ('08), Gerard ('09), Meek ('12) and de Sinety 

 ('01). Davis and Meek find definitely 17 chromosomes and 

 Gerard suggests the same as his best enumeration. De Sinety 

 does not give definite evidence on this point. According to 

 Davis the largest 3 pairs are bent rods and have non-terminal 

 fiber attachments at the points of curvature; the remaining 5 

 pairs are normal rod-shaped elements with terminal attachments. 

 In these matters Meek agrees, and, while the descriptions of Gerard 

 and de Sinety are not definite and specific, their general statements 

 and figures substantiate Davis' findings. The accessory chromo- 

 some is not unusual in its behavior. 



My own studies have extended over more than forty genera 

 of Acrididae as follows: Acrolophitus, Aeoloplus, Amphitornus, 

 Arphia, Aulocara, Boopedon, Brachystola, Camnula, Chloealtis, 

 Clinocephalus, Dactylotum, Dissosteira, Encoptolophus, Erem- 

 nus, Hadrotettix, Hesperotettix, Hippiscus, Mecostethus, Melan- 

 oplus, Mermiria, Mestobregma, Orphulella, Paroxya, Philbos- 

 troma, Phrynotettix, Phaetaliotes, Proracorypha, Pseudopomala, 

 Psinidia, Rhomaleum, Schistocerca, , Scirtettica, Spharagemon, 

 Stenobothrus, Syrbula, Trimerotropis, Tropidolophus, Tryxalis. 

 In all these the same conditions were found as have been de- 

 scribed for Hippiscus regarding the number of chromosomes, 

 their sizes and forms, the attachment of the fibers, arrangement 

 in the metaphase and behavior during division, with the exception 

 of Stenobothrus, Chorthippus, Mermiria, Hesperotettix, Chloealtis, 

 some species of Trimerotropis and, occasionally, Chortophaga. 

 In Stenobothrus there is the same apparent difference in number, 

 shifting of fiber attachment in certain chromosomes and differ- 

 ence in form and behavior in these elements as have been de- 

 scribed by other investigators. Hesperotettix and Mermiria have 

 the association between the accessory chromosome and certain 

 of the euchromosomes that I have elsewhere described ('05) 

 which produces an apparent change in the behavior of the com- 

 plex, while a certain individual of Chortophaga in the early nymph 

 condition showed a spermatogonial synapsis of 4 pairs of chromo- 

 somes. 



