6 4 



THE ANIMAL PARASITES OF MAX 



gliding movement as well as in the encystment. The thin ectosarc then 

 follows, and this also forms the transverse partition between the protomerit 

 and deutomerit, its deepest part frequently exhibiting circular rows of 

 muscles (myophane, myoneme) on both sections. The principal mass of 

 the body consists of the very granular endosarc, the large or small, and usually 

 round, granules being composed of paraglycogen, fats and other materials. 

 Some of the gregarines perform peristaltic or worm-like movements, even 

 in the mature condition (fig. 19), others glide along in 

 the contents of the intestine without any visible change 

 of form like diatoms in water. According to Schewiakoff ,' 

 this is effected by the secretion of a slimy matter which 

 soon, stiffens at the posterior end of the body, adheres 

 to the surface on which the creature rests and propels 

 it forward. It is likewise this secretion, originating from 

 the slime-secreting layer, which enables the gregarines 

 (clepsidrinidae) living free in the intestine, to adhere one 

 to the other in rows. 



Propagation of the gregarines may be effected in 



two ways. Sporula- 

 My. tion, which takes 

 place during encyst- 

 ment, has long been 

 known. Moreover k 

 at all events in a 

 few simpler forms, 

 the so-called schizo- 

 gonia may take place 

 within the same host, 

 the qntire body (after 

 division of the nu- 

 cleus) separating into 

 several nucleated 

 segments (merozo- 

 ites), each one of 

 which becomes a 

 gregarine directly. 2 



Sporulation is generally brought about by the fusing together of two con- 

 tiguous gregarines and their consecutive encystment (fig. 22). Encystment 

 in Ceratospora is said to be omitted or may be confined to one individual 

 (as in Actinocephalus dujardini} ; in exceptional cases three individuals may 



FIG. 20. Xiphor- 

 hynchus firmus. 

 Leg. With the 

 epimerit fixed in an 

 intestinal epithelial 

 cell ; host Dermestes 

 lardarius; enlarged. 

 (After Leger.) 



G. E. 



FIG. 21. Clepsidrina munieri, 

 Schneid. ; from Chrysomela hce- 

 moptera. Section of the surface, 

 1,500 times enlarged. (After 

 Schewiakoff). Cu. = Cuticle ; E. 

 = Ectosarc. G. = Gelatinous 

 layer. My. = Myophane. 



1 Schewiakoff, " Ueb. d. Ursache d. fortschreit. Beweg. d. Greear " (Z. f. w Z 1804 

 Iviii., p. 340). 



- Cf. Schneider, A., " Ophryocystis biitschlii" (Arch. Zool. exp., 1884, 2, ii., p. in ; 

 " Ophr. francesci" (TabL zool., 1885, i., p. i). Caullery et Mesnil., " Sur une Greg, 

 ccelom. pre's. dans son cycle evolut. une phase de multipl. asporulee " (C. R. Ac. sc., Paris, 

 1898, cxxvi., p. 262 ; C. R. soc. biol., Paris, 1898, v., p. 65). Leger et Hagenmuller, 

 Morph. et evolut. de I'Ophryoc. schneideri" (Arch. Zool. exp., 1900, 3, viii . ; Notes 

 No. 3). Leger, " Nouv. Sporoz. des law. d. Dipt." (C. R. Ac. sc., Paris, 1900,' cxxxi., 

 p. 722.) Caullery and Mesnil, " Parasit. intracell. et la multi-blic. asexuec d ere* " (C R 

 soc. biol, Paris, 1901, liii., p. 84). 



