H-^MOSPORIDIA 85 



unheeded, although they confirmed the occurrence of foreign bodies, com- 

 pared by Lankester (i) to pseudo-navicella (spores of gregarines), in the. 

 blood of amphibia. It was only after Gaule (2) had rediscovered the 

 " little blood-worms " (cytozoa) that more general attention was directed 

 to the matter, perhaps because of the interpretation given by the author 

 to his discoveries, and they were declared to be normal constituents of 

 animal cells. 



In contradiction, Ray Lankester (3) declared that the cytozoa were 

 of a parasitical nature and gave the name of Drepanidium ranarum to 

 the species observed in the frog, which Chaussat 1 had called Anguillula 

 minima. In this case he considered the parasite to represent a develop- 

 mental stage of a still unknown gregarine. Their independent nature was 

 finally confirmed by the works of Danilewsky (4) ; this investigator discovered 

 analogous forms in the blood of lizards (Lacerta viridis and L. agilis) and 

 of tortoises (Emys lutaria\ and he described their development, which takes 

 place in the blood. 



Several years previously a French military doctor in Constantine, by 

 name A. Laveran (5), had observed hyaline pigmented forms in the fresh 

 blood of malarial patients- clinging to the - red blood corpuscles. On 

 noticing the appearance of " flagclla " on these organisms which suddenly 

 made lively movements, the thought occurred to him that they were the 

 parasites (first termed Oscillaria malaria and later Hcejnatozoon malarice 

 of malaria, intermittent fever, ague). Although Richard (6) soon after con- 

 firmed Laverari's discovery and extended it by finding the still unpigmented 

 early stages, these communications were subjected to lively opposition, 

 because at this period it was generally believed that malaria was caused 

 by a bacillus (Klebs, Tommasi-Crudelli). The investigators who afterwards 

 pursued the subject (Marchiafava, Celli, &c.), asserted that the objects 

 seen were merely evidences of degeneration of the red blood corpuscles, 

 the haemoglobin of which was changed into melanin without the intervention 

 of a parasite. However, when Marchiafava and Celli (7) saw the amoeboid 

 movements of Laveran's parasites they fully recognised their animal nature. 

 The name Plasmodium malarice, usually given to the malarial parasites, 

 emanated from these authors, and although unsuitable, according to the rules 

 of nomenclature, it replaces the older and valueless term Oscillaria, and is 

 still in use. 



On the abandonment of the opposition to Laveran's doctrine, numerous 

 authors commenced a careful study of the malarial parasites, so that by 

 the beginning of the 'nineties certain conclusions had been arrived at. We 

 had learned to know the difference of the parasites that caused the various 

 forms of malaria, as well as their development in the blood, and confirmed 

 the fact that the blood of malarial patients inoculated into healthy persons 

 produced in the latter malaria oi the same type as that from which the 

 patient suffered (Gerhard t (8) Bignami and Bastainelli (9) and others). After 

 Danilewsky (10) discovered the occurrence of disease-producing endoglobular 



1 Neither the name of the genus nor species can be retained, the former because 

 already in 1869 it was given to an infusorium by Ehrenberg, and 'the latter because 

 the species had already been named by Chaussat in 1850. Labbe has, therefore, 

 given to Drepanidium, Lank., the name of Lankesterella ; the correct designation of the 

 species is therefore Lankesterella minima (Chauss.). 



