68 THE ANIMAL PARASITES OF MAN 



usual condition, in so far as the sporozoites likewise do not penetrate into 

 the epithelial cells, but only fasten themselves on the latter by one pole, which 

 ultimately becomes the epimerite. Finally, the intra-cellular phase may be 

 of short duration, and multiplication by schizogony may take place during 

 the same. 1 



For the classification of the gregarinidia refer to the literature as follows : 

 / 



LITERATURE. 



DUFOUR, L. Note sur la greg. (Ann. sc. nat., 1828, i, xiii., p. 366). 



KOELLIKER, A. Beitr. z. Kenntn. nied. Th. I. Ueb. d. Gttg. Gregarina (Z. f. w. Z., 



1848, i., p. i). 



STEIN, F. v. Ueb. d. Nat. d. Greg. (Arch. f. An. u. Phys., 1848, p. 182). 

 LIEBERKUHN, N. Evol. d. Greg. (Mem. cour. et mem. d. sav. etrang. Acad. belg., 



1855, xxvi). 

 SCHMIDT, A. Beitrag zur Kenntniss der Gregarinen und ihrer Entwickelung (Abhdl. 



d. Senckenb. naturf. Ges. in Frankf. a. M., 1854, i., p. 161). 

 BENEDEN, E. v. Rech. sur 1'evolution des Gregarines (Bull. Acad. roy. belg., 1871, 



2, xxxi., p. 325). 

 GIARD, A. Contribution a 1'hist. nat. des Synascidies (Arch. d. Zool. exp. et gen., 



1872, ii., p. 841). 

 SCHNEIDER, A., in Arch, de Zool. exp. et gen., 1873, ii., p. 515 ; 1875, iv., p. 493 ; 1882, 



x., p. 423 ; 1884, 2, ii.. p.i; and the zoological tables issued by the same author). 

 BUTSCHLI, O. Kleine Beitr. z. Kenntniss d. Gregarinen (Z. f. w. Z., 1881, xxxv., p. 384). 

 LEGER, L. Rech. sur les gregarines (Tabl. zool., 1892, iii., p. i). 

 F'RENZEL, J. Ueber einige in Seethieren lebende Gregarinen (Arch. f. mikr., An. 



1885, xxiv., p. 545). Argentin. Gregarinen (Jen. Zeitsch. f. Naturwiss, 1892, 



xxvii., p. 233). 

 LEGER, L. Nouv. rech. sur les cyst Polyparas. d. Arthrop. terr. (Ann. de la Fac. 



d. sc. de Marseille, 1899, vi., No. 3. Sur un nouv. sporozoaire des larves de 



clipter (C. R. Ac. sc., Paris," T., 1900, cxxxi., p. 722). 



Order 2. Coccidiida. 



Hake(i) first saw the formations we now term Coccidia during his investi- 

 gations on the so-called coccidial nodules of rabbits. The opinions as to the 

 nature of these peculiar formations were very diverse ; the discoverer con- 

 sidered them to be a sort of pus corpuscle ; Nasse (2) took them for epithelial 

 cells of the biliary passages, others for helminthes, especially the ova of 

 trematodes (Dujardin, Kuchenmeister, Gubler, &c.)- Remak(3) was the first, 

 to draw attention to their relation to the Psorospermia (Myxosporidia), and 

 this investigator found them also in the small intestinal appendix of 

 rabbits. Lieberkiihn (4), who not only examined the coccidia of rabbits, but 

 found similar forms in the kidneys of frogs, likewise calls them outright 

 psorospermia ; and to differentiate Miiller's psorospermia, which are found 

 in fishes, 'from those of rabbits, &c., the latter were called oval or globular 

 (Eimer) (5), until R. Leuckart (6) named them " Coccidia " and placed them in a 

 group of the sporozoa analogous to that of the Gregarinida, Myxosporidia, 

 &c. Numerous works confirmed the occurrence of coccidia, not only in all 

 classes of vertebrate animals, but also in invertebrates (mollusca, myria- 

 poda, annelida, &c.), and numerous genera and species have in the course 

 of time been described which inhabit the epithelium of the intestine and 



1 Compare Caullery and Mesnil, " Le paras. intracelL et la multi-pi, asexue d. 

 (C. R. soc. biol, Paris, 1901, liii., p. 84.) 



