BLEMOGREGARINA LACERTARUM 



785 



extremity is rounded and the posterior pointed, but when in motion the anterior 

 end also becomes pointed and so enables the parasite to penetrate the red cells ; 

 and further during movement one or two constrictions may be seen which beginning 

 at the anterior end seem to slide towards the posterior end in a sort of peristaltic wave. 

 The nucleus is situated about the centre of the parasite and at the posterior end there 

 is often seen a structure of variable appearance which probably represents the 

 debris of the red cell in which the Drepanidium developed or of the membrane 

 which enveloped the intra- corpuscular parasite. 



The young intra- corpuscular parasite is represented by a small nucleated cell 

 with granular protoplasm, of variable shape, measuring 4-8/a in its longest diameter. 



FIG. 380. Httmogregarina ranarum, (After Laveran.) 1, Endo-corpuscular parasite : 

 2, free heemogregarine : 3, free hsemogregarine with flagellum : 4, Haemogregarine fixed 

 and stained : 5, Haamogregarine with constriction ; 6, Reproduction forms. 



As the parasite grows it becomes longer and is occasionally bent upon itself. It 

 sometimes happens that there may be two parasites in the same red cell and 

 leucocytes are also at times infected. 



(ii) Reproduction forms are never found in the blood of the peripheral circulation : 

 for the study of this phase of the life history films must be prepared from the spleen. 



The parasites are numerous in the spleen even when very few can be found in 

 the blood-stream. Reproduction forms consist of spherical or irregular cells 4-8/x 

 in diameter each containing two to six chromatin masses which stain deep violet 

 with haematein. They are very similar to those of H cemogregarina stepanowi and 

 represent an endogenous phase of reproduction (Laveran). According to Billet, 

 exogenous reproduction by sporogony takes place in a leech of the genus Helobdella. 



Methods of examination. Blood is obtained by pricking a toe. In other 

 details the technique is the same as described under H cemogregarina stepanowi. 



3. Htemogregarina lacertarum. 



Hsematozoa are frequently found in the blood of lizards (Lacerta viridis, 

 L. agilis and other species) and several species have been described by Danilew- 

 sky, Chalachnikoi? and by Labbe, H cemogregarina lacertarum, Danilewskya 

 lacazei, etc. 



The young intra- corpuscular parasites are rounded or oval nucleated cells, but 

 they afterwards elongate to form vermicules measuring about W/JL long and more 

 or less bent upon themselves. The parasite is set free by the destruction of the 

 infected red cells and then shows active gregarinoid movement, sometimes accom- 

 panied by swellings and constrictions passing like waves along the body. Repro- 

 duction forms are not found in the blood of the peripheral circulation. 



Methods of examination. Blood can be obtained by cutting the tip of the 

 tail. Films should be prepared and stained in the manner indicated above. 



3D 



