PROTOZOA WITHOUT MOTILE ORGANS 65 



Questionable genera of coccidiida are the following: 



Hyaloklossia, Labbe, 1896, from the frog. 



Goussia, Labbe, 1896, from various species of fish. Usually classed as Coccidium 

 species (Fig. 20, M, X). 



Bananella, Labbe, 1895, from the gut of Lithobius. Usually classed with Coc- 

 cidium. 



Rhabdospora, Laguesse, 1895; Gonobia, Mingazzini, 1892; Pfeifferella, Labbe, 

 1899; Molybdis, Pachinger, 1886; Cretya, Mingazzini, 1892; Gymnospora, 

 Moniez, 1886, are all probably species of Coccidium. 



Order 3. Hemosporidia, Danilewsky. Blood dwelling sporozoa cytozoic or celo- 

 zoic in mode of life in the blood constituents, and with or without alternation 

 of hosts. A somewhat heterogeneous collection of parasitic protozoa with 

 obscure affinities, pointing in part toward the flagellates, in part toward the 

 coccidia. For convenience, and purely as a temporary matter, we follow 

 Minchin in dividing the order into two suborders, Acytosporea and Hemo- 

 sporea, the former including those blood -dwelling forms which seem to bear 

 some relationship to Crithidia and Herpetomonas, the latter including the 

 more Coccidia-like forms. 



Suborder A. ACYTOSPOREA. The trophozoite is an intracellular or intracorpus- 

 cular parasite which usually completes its schizogony within the host cell. 

 The sexual cycle is completed in the digestive tract or body cavity of some 

 intermediate host in all known cases some species of blood-sucking arthro- 

 pod, usually an insect or arachnid. 



Genus 1. Plasmodinm^ Marchiafava and Celli, 1885. The organisms of human 

 malaria are all referred to this genus. The characteristic morphological 

 features are the presence of melanin pigment, oval merozoites grouped around 

 a central residual body, and spherical or crescentic gametes. Sporogony in 

 the gut and body cavity of mosquitoes of the genus Anopheles. Three species 

 generally recognized P. vivax, Grassi and Fek'tt i, 1 N92, the cause of tertian 

 fever, with schizogony every forty-eight hours. P. malaria-, Lav., 1880, the 

 cause of quartan fever, with schizogony every seventy-two hours. P. immacu- 

 latum Gr. and Fel., 1892, the cause of pernicious malaria, with subspecies 

 according to Craig and others, exhibiting quartan and tertian characteristics. 

 This last species is generally held to be a distinct genus under the name 

 Laverania, Gr. and Fel., 1890, but Schaudinn's contention that crescentic 

 instead of spherical gametocytes is an insufficient distinction for generic 

 difference is rapidly gaining ground, and we follow it here. Minchin's 

 remark (footnote, p. 267, 1903), that the popular names given to the malaria- 

 causing parasites ("tertian," "quartan," and "pernicious") are more intel- 

 ligible and less misleading than the so-called scientific names, is confirmed 

 by Liihe, but it seems to us that such confusion is only further aggravated 

 by their retention of the generic name Laverania. In addition to the species of 

 Plasmodium causing human malaria, La veran described a species from the 

 blood of apes under the name of P. kochi, and Liihe places in the same 

 species the blood parasites of chimpanzees from Kamerun. 



Subgenus. Hemoproteus, Kruse, 1890. The cause of bird malaria. Merozoites 

 and schizogony as in the preceding, sporogony in the digestive tract and body 

 cavity of mosquitoes of the genus Culex. Gametocytes bean-shaped. The 

 various species of this genus are now commonly referred to the genus Plas- 

 modium. Common in birds. 



Genus 2. Babcsia, Starcovici, 1893. (Syn., Pyrosoma, Smith and Kilb.; Piro- 

 plasma, Patton.) An intracorpuscular parasite of mammalian blood. Tro- 

 phozoites usually piriform, without pigment, and reproducing by simple 

 division or by budding within the blood corpuscle. Transmission by ticks 

 and sporogony in the hitter's gut. 

 5 



