47^ 



TELOSPORIDIA 



A. Without hcamozoin : — 



I. Live in red and white blood cells in the peripheral 



blood — -HcBmogregannidcB. 

 II. Live in white cells in the organs — Toxoplasmidce. 

 III. Live in red cells in the peripheral blood— P^Vo^/^zs- 

 midcB. 



B. With hcemozoin : — • 



I. Ookinete encysts and forms an oocyst — Plasmodidce, 

 II. Ookinete is not known to encyst — HcBmoproteidcE. 



Fig. 



-HCB- 



Family H^mogregarinid^e Neveu-Lernaire, 1901* 



Synonyms.— H(^wos/?onf^2a Labbe, 1894; Hcsmosporea Minchrn., 1903. 

 Definition. — Telosporidia, in which either the gametocytes or the schizonts, 

 or both, are present in red or white cells in the peripheral blood of vertebrates, 

 and in which schizogony takes place either in the cells of the peripheral blood, 

 or in those of some organ, while sporogony takes place in the body of some 

 blood-sucking invertebrate, such as a leech, a tick, a mite, or an insect. 

 Neither schizonts nor sporonts contain hsemozoin. 



History. — Although the first haemogregarine was dis- 

 covered in a frog as far back as 1850 by Chaussat, who 

 thought it was a nematode, it is only quite recently, owing 

 -to the labours of Sambon, Miller, Miss Robertson, Christo- 

 phers, and others, that any accurate knowledge has been 

 obtained. 



The evolution of the knowledge concerning these para- 

 sites may iDe briefly stated. 



Discovered, as mentioned above, by Chaussat, they were 

 next seen by Ray Lankester in 1871, and thought to be a 

 stage in the life-history ot the frog trypanosome, T. {Un- 

 dulina) rotatorum, and then by Gaule in 1880, who mistook 

 them for cell inclusions. In 1 8 85 Danilewsky first applied 

 the name ' Hsemogregarina ' to the parasites he found in the 

 blood of tortoises and lizards. In 1 894 Labbe classified them, 

 according to the relationship between the length of the 

 parasite and that of the blood cell, into (i) Drepanidium, 

 parasite not more than three-quarters of the length of the host cell; {2) Kavyo- 

 lysus, parasite not exceeding host cell in length, and destroying the nucleus ; 



(3) Danilewsky a, parasite exceeding the host cell in length, and bent upon 

 itself. 



The term Drepanidium having been previously employed for one of the 

 Heterokaryota, it was necessary to alter it to Lankesterella, and the term 

 Danilewsky a was also altered by Danilewsky in 1897 to ' Haemogregarina ' 

 {sensil sfricto) ; but since Sambon and others have described so many new 

 species this classification no longer stands, nor can a natural arrangement be 

 proposed until the life-histories of the various species are fully known; there- 

 fore the suggestion of Laveran is being universally adopted, which consists of 

 arranging them according to the classes, orders, and genera of the hosts, and 

 distinguishing only one genus, Hcemogregarina Danilewsky, 1885, the various 

 species of which are arranged into four groups: (i) Haemogregarinida of 

 mammals; (2) Haemogregarinida of reptiles ; (3) Haemogregarinida of amphibia; 



(4) Haemogregarinida of fish. With regard to the Haemogregarinida ot mam- 

 mals, they were first discovered by Bentley in the blood of a pariah dog {Canis 

 familiaris) in Assam, and confirmed by James in 1905. In 1905 Balfour 

 discovered Hcsmogregarina jaculi Balfour, 1905, in Jaculus gordoni in 

 Khartoum, and described the cycle of scliizogony; but though numerous ex- 

 periments were conducted with Xenopsylla cleopatrcB, species of Dermanyssus 

 (mites), and Clinocoris rotundatus, only the liberated gametocytes have been 



147. 



mogregarina 

 cantlei Sambon. 



(After Sambon.) 



