140 SPOE.OZOA. 



66. Haemogregarina xavieri de Mello. (Fig. 65.) 



■\Heemogregarina xavieri, de Mello, 1932, pp. 1426-27, pis. iii & iv. 



Two forms present : (1) Broadly ova] or sometimes reniform, 

 occupying, according to the state of its development, a greater 

 or less extent of the corpuscle. Cytoplasm alveolar, containing 

 generally two, sometimes more, rounded vacuoles, usually 

 confined to the polar regions. Nucleus central, containing 

 granules or rods of chromatin in compact masses or variously 

 dispersed. The parasitized corpuscles are generally not 

 altered, sometimes reduced or enlarged in size, and the nucleus 

 of the corpuscle is displaced to one side. (2) Elongate or 

 vermicular forms, sometimes enclosed in a fine, membranous 

 capsule or entirely without a capsule, provided with a tail 

 which stands out from the body, and does not exceed one- 

 quarter or one-third of its length. These tailed forms are 

 much less numerous than the oval forms. One pole sometimes 

 presents one or two vacuoles, but generally the c3rtoplasm 

 alveolar, and the vacuoles not clearly indicated. Nucleus 

 central, and the chromatin showing the same disposition as in 

 the oval forms. The metachromatic granules generally 

 abundantly distributed in the tail, and rarely in the anterior 

 pole as well. Forms intermediate between the oval and the 

 vermicular are also met with, and sometimes two individuals 

 are seen in the same corpuscle. 



Schizogony takes place in the lungs, spleen, liver, etc. 

 Cysts found in smears from the lungs are oval, and contain 

 2 or 3 schizonts ; those found in smears from the spleen are 

 rounded or oval, and contain 6 or 7 schizonts ; while those 

 in smears from the hver are circular or more or less oval, 

 and contain 2 or 3 schizonts. In sections of parasitized organs 

 oval cysts are found to contain 6 or 7 schizonts (merozoites) 

 similar to those met with in the smears. Fusiform merozoites 

 are seen in the blood-stream and in the intercellular spaces. 



Dimensions. — Oval form 7-5-13-5/a in length by 2-5-6-2/x 

 in width ; vermicular form 9-10//, in length by 4ju. in width ; 

 cysts from lungs 8-10 ju, by 4-5 ju,, from hver, spherical, 15 ju, in 

 diameter, or oval, 8-5//, by 5/x or lOjU, by 7-5 jU. 



Remarks. — The species is morphologically distinct from 

 H. laverani Simond, described from the same host at Agra. 

 Both H. malabarica and H. xavieri do not show any amoeboid 

 young stages, nor do they show the two refringent granules 

 so characteristic of H. laverani. H. xavieri differs from 

 H. malabarica in the tail being considerably shorter, and not 

 being closely appHed to the body, the nucleus being central in 

 the elongate forms, and in the dimensions being considerably 

 smaller in both elongate and oval forms than in the other 

 species. 



