A Study of Some Gregarines 21 



hiscing- by rupture of the wall; sporulation,— complete to partly 

 complete ; sporocysts,^ — oval. These characters place the gregar- 

 ine from Melanoplus in the family Gregarinidae. Further than 

 this the gregarine does not seem to be exactly conformable, but 

 since it comes nearest to the genus Hirjuocystis, it may be placed 

 in that genus for the present at least. 



The most careful search for an intracellular stage of this gre- 

 garine shows nothing that can be called such. There are numer- 

 ous cellular inclusions, but these are undoubtedly the hyaline and 

 chromatin waste and degeneration products wdiich have been so 

 well studied by Leger and Duboscq (1902-4) and which for years 

 had deceived such workers as Butschli, Aime Schneider et al. 



The measurements of some of the gregarines which I find free 

 in the intestines and caeca are as follows, 103 «,, 120 /*, 91 /*, and 

 73 IX. So that the gregarine 73 /x long is not intracellular, though 

 the intestinal cells of the host range from 80 /x to 170 /a in height 

 and might readily hold a gregarine of that length. To determine 

 the nature of the sporozoite development and its relation to the 

 intestinal epithelium will probably require some artificial infection 

 experiments. 



The gregarines from Chiuiaroccphalus and Eritcttix have not 

 yet been studied sufficiently to permit of a satisfactory descrip- 

 tion at this time though the writer hopes to complete a study of 

 these forms in the near future.- Figure 12 shows a view of a per- 

 manent mount of the gregarine from Chimarocephahis. It will 

 be noticed that the nucleoli are visible in loops, as Wasielewski 

 (1896) gives for Lophocephalus insignis. 



Search was made for Hirmocystis rigida in the vicinity of Col- 

 orado Springs, Colorado, and at St. Peters, about fifteen miles 

 from Colorado Springs, but of the numerous specimens of Me-^ 

 lanophis that were examined none were infected. At Canon City, 

 Colorado, the infection was extensive, at least half of the speci- 

 mens of Melanoplus being infected with from two or three to 

 several hundred parasites. The common species of Melanoplus 

 at Canon City are hivitattus, differentialis, and angiistipennis. 

 In these locusts the gregarines were never found outside of the 

 intestine in the bodv cavitv, but were sometimes on the outside of 



169 



