PROTOZOA IN BRITISH EAST AFRICA 
31 
detected in other rodents, but the trypanosome does not appear 
to multiply freely. Trypanosomes possessing somewhat similar 
morphological characteristics, but which are specific for their 
hosts, have been found in the Rabbit ( T . cuniculi, Blanchard) 
and Mouse (T. duttoni, Thiroux). Novy and McNeal, who were 
the first to succeed in the artificial cultivation of trypanosomes, 
made use of this species and obtained quite vigorous growths 
on a medium composed of blood-agar. 
Sub-phylum, Syorozoa. 
Class, Telosyoridia. Schaudinn. 
Order, Haemosjporidia. Danilewsky. 
Minchin divides this order into two sub-orders : — 
1. Haemosyorea, to include the genera Lankeslrella (Labbe, 
1899), Karyolysis (Labbe, 1894), and Haemogregarina (Danil- 
ewsky 1885), all of which are parasites on the red blood 
corpuscles of cold-blooded vertebrates, — fish, amphibians and 
reptiles. 
2. Acystosyorea. These forms are parasitic in the red blood 
corpuscles of warm-blooded mammals and birds, and require 
a second host, a blood-sucking arthropod, to bring about 
transmission. It is usual for the parasites to exhibit both 
a sexual (sporogony) and an asexual (schizogony) mode of 
development. 
Schizogony takes place in the vertebrate host and Sporogony 
in the arthropod. In many cases the actual stages of develop- 
ment — more especially in Sporogony — have not yet been fully 
worked out, but the connexions of Malaria with mosquitos, 
East Coast Fever and Redwater with ticks, will serve as examples 
of this alternation in generation. The principal genera of the 
Acystosporea are Plasmodium and Laverania, which includes the 
malarial parasites of man and monkeys ; Haemoyroteus and 
Halteridium, to which the very common parasite of the red 
blood corpuscles in birds belongs ; and the genera Babesia, 
Theileria and Nuttallia, which are parasitic on, or found in, the 
red blood corpuscles of the domestic animals. We only dis- 
cuss here the last three genera, all of which in nature require one 
of the tick family (Ixodidae) to effect transmission. 
