114 NATURAL SCIENCE. August, 1896. 



Three species oi Drepanidiiim are distinguished : two occurring in the 

 red-corpuscles of frogs, and one in those of birds. Karyolysus and 

 Danilewskya are very similar forms, the species of which occur in the 

 blood of lizards, tortoises, and frogs. The (as it seems to me) really 

 closely-related Acystosporidia occur chiefly in the red-corpuscles of 

 birds, but also in salamanders, tritons, and frogs. The most 

 important of these is the " organism of malaria," to which Professor 

 Grassi has given the name Hcsmamceba Lavevani — after Laveran, who 

 found it in 1880 in the blood-corpuscles of men suffering from 

 malaria. The sporulation of the parasite was described by Marchia- 

 fava and Celli in 1888. Golgi showed that the access of fever had a 

 definite relation to the development of the parasite. Black pigment 

 granules, formed by the destruction of the hsemaglobin of the blood- 

 corpuscle in which it is parasitic, are characteristic of the Hamamceba 

 of malaria. The crescent-shaped pigmented bodies seen in the red- 

 corpuscles of malarial patients are a phase of the growth of this 

 parasite. An account of the recent work of Marchiafava, Bignami, 

 and Mannaberg, with drawings of various parasites of malarial fever, 

 was given by Dr. J. W. Gregory in Natural Science for September, 

 1894 (vol. v., pp. 195-201). Glugea bombycis is the name now assigned 

 by Thelohan to the " pebrine corpuscles " of the silk-worm, studied 

 by Pasteur, and this organism is ranked among the Myxosporidia. 

 The suggested but doubtful relationship to Sporozoa of the corpuscles 

 observed in cancer-cells is not touched on in the present treatise. 



Extremely numerous as are the parasitic Protozoa included 

 under the group " Sporozoa," it is well to remember that there are a 

 number which are referable to the Flagellata, and are not treated of 

 by Wasielewski in his book. This is to be regretted, since there is 

 very close affinity between some of the parasitic Flagellata and the 

 blood-parasites referable to the Sporozoa. The late Timothy Lewis 

 and others have described remarkable elongate Flagellata [Heypetomonas 

 lewisii, Sav. Kent.) from the blood of rats and other animals, and, just 

 lately, it has been suggested as probable that the Tsetze fly of South 

 Africa owes its deadly character to the fact that it is the means of 

 carrying a parasite, which appears to be one of the Flagellata, from 

 one animal to another. It is to me by no means clear that these 

 haematozoic Flagellata are widely separable from haematozoic 

 Sporozoa, whilst some of the parasitic Monadina of Cienkowski, 

 referred by some writers to Mycetozoa, stand very close. The three 

 groups, Flagellata, Sporozoa, and Mycetozoa, are in many respects 

 closely allied. Perhaps the essential cell-parasitism of the Sporozoa 

 is the chief point in which they differ from parasitic Flagellata and 

 from Mycetozoa. The field of work offered by parasitic Protozoa is 

 still one which will yield most important results to the skilled micro- 

 scopist with zoological training. Such works as that of Dr. von 

 Wasielewski furnish real help to the would-be investigator. 



E. Ray Lankester. 



