A H^MOGREGAEINE OF MAMMALS 99 



deep Romanowsky purple, anrl frequently did not stretch wholly across the parasite, and in 

 tile large pale-staining area three or four spherical i-liromatin dots were often to be oliservcd. 

 (Plate XI., Fig. ,1.) 



Professor Laveran has seen this [ireparation and points (lut tliat sncli [)ecnliaritics in 

 morphology frequently occur. He does not regard these as special sexual forms. At first I 

 \vas inclined to consider the parasite as being allied to the halteridium of birds. I noted, 

 however, that it was not pigmented, was not curved so much as the halteridium forms, and 

 never exhibited the spore formation at either end as iloes Hdlti'ruHnm (Innilcwsh/i. 



Endoglobular H^mogregarine of this Class not Found Previously in 

 THE Eed Corpuscles of Mammals 



As Professor Laveran kindly pointed out to me, and as indeed was soon apparent from -Apparently the 

 a study of the literature, especially Professor Miuchin s treatise* on the sporozoa, this garine found 

 parasite of the jerboa closely resembles the ffceinoi/rcgariiiidce of cold-blooded vertebrates. '" mammals 

 This fact is of extreme interest, as at the time I encountered it, I am unaware that any 

 endoglobular parasite of this class had been described in the blood of mammals. Since then 

 I have seen Christophers' descriptit)nt of a very similar parasite which affects the red cells of 

 the Indian Gerbil (GiThilliis iii(Ilcii.t). Bentleyij: in 1905 produced a paper on a leucocytoziion Various 

 of the dog in Assam, and it has been more fully described by James. § Another leucocytoziion ™'^°'^^ 

 of mammals has been found by Patton in the palm squirrel of India, while I will shortly 

 make reference to a similar parasite which I found in rats at Khartoum. The classification 

 of tjiis onler of jiarasites given by Professor Minchin is as follows: — 



" Order Ihvmosporidia (Danilewsky). 



" Sub-order 1. Hcemofsporea . 



"Genus i. Lanl-CKtrrdIa (Labbe, 1899) f(ir Dri'jKinuliitm (Lankester). The 

 hajmogregarine is not more than three-quarters the length of the blood corpuscle it inhabits. 



"Genus ii. Karii<)lii!<u!< (Labbe, 1894). The hiemogregarine does not exceed the 

 corpuscle in length. 



" Genus iii. Hceinof/rivariiic (Danilewsky, 1897) (syn. Danilewsky-Labbe, 1895). 



" The body of the parasite when adult exceeds the corpuscle in length and is bent on 

 itself within it in a characteristic manner like the letter V." 



Now the parasite of the jerboa in question does slightly exceed the corpuscle in length, 

 but is only slightly curved. It looks, as a rule, as if it had outgrown its corpuscle, and 

 sometimes the remains of what has evidently been a distended and distorted corpuscle can be 

 seen lying around it. The large swollen and bloated forms are much larger than the 

 corpuscles which originally contained them and are found lying free. On several occasions, 

 and especially in fresh preparations from the bone-marrow, I have noted forms slightly 

 turned up at one end and looking like an incomplete letter V. (Plate XL, Fig. //.) As True haemo- 

 stated, I have not often been able to demonstrate this appearance in stained specimens, ibr'm'"^' 

 Christophers saw forms of his parasite in the act of leaving the red cells. I have never 

 witnessed such exits. Like Christophers I have failed to find forms in the act of invading 

 the erythrocytes, but like him I have often seen two forms lying in such close apposition 

 as to suggest that fission had occurred. Each, however, possessed a separate capsule and 

 doubtless the appearance was due merely to the infection of two neighbouring corpuscles. 



• Minchin. A Treatise on Zoology (Lankester), 1903. Part I., Sporozoa. 



t Scientific Memoirs by Officers of the Medical and Sanitary Depts. of the Gov. of India, 1905, No. 18. 



t Brit. Med. Jour., May 6th, 1905, p. 888. 



§ Scientific Jlemoirs, India, 1905, No. 14. 



