PROTOZOA WITHOUT MOTILE ORGANS 65 



Questionable genera of cocckliitla are the following: 



Hyaloklossia, Labbe, 1S9(3, from the frog. 



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

 species (Fig. 20, M, X). 



Bananella, Labbe, 1S95, from the gut of Lithobius. Usually classed with Coc- 

 cidium. 



Rhabdospora, Laguesse, 1895; Gonobia, INIingazzini, 1892; Pfeiflerella, Labbe, 

 1899; INIolybdis, Pachinger, 188(5; Cretya, ^lingazzini, 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 jiarasitic 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 

 Minehin in dividing the order into two suborders, Acytosjiorea 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 intracorjnis- 

 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. Pla.sniodiiim, IMarchiafava 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 Feletti, 1892, 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 (rr. and Feb, 1892, the cause of pernicious malaria, with subspecies 

 according to (^raig and others, exhibiting quartan and tertian characteristics. 

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

 Laverania, Gr. and Feb, 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, j). 267, 1903), that the popular names given to the malaria- 

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

 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, Laveran des?ribed a species from the 

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

 species the blood parasites of chimpanzees from Kamerun. 



Subgenus. IlniioprofeuK, Kruse, 1S90. The cause of bird malaria. INIerozoites 

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

 cavity of mos(|uitoes 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. Bnhr.v'a, Starcoviti, ],S93. (Syn., Pyrosoma, Smith and K'ilii.; Piro- 

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

 phozoites usually piriform, without pigment, and rf|)roducing by simple 

 division or in' budding within the i)l()0(l corpuscle. Transmission by ticks 

 and sporogony in the latter's gut. 

 5 



