PROTOZOA IN BRITISH EAST AFRICA 
23 
flagellated and ciliated organisms parasitic in the intestinal 
tract of apparently healthy animals, nor of the important 
genus of the Sporozoa — Coccidia — one member of which has 
been found in association with a serious disease of cattle. 
The preliminary classification of the Phylum Protozoa is 
made on the character of the means of locomotion, four sub- 
phyla being recognised. 
1 . Sarcodina, a group possessing pseudopodia ; includes 
the Amoebae, some of which are pathogenic. 
2. Mastigophora, in which mobility is due to one or two 
flagella. The trypanosomes are included in this group, as 
also are the Spirochaeta, though the morphology of the latter 
affords much scope for debate as to the propriety of their 
inclusion here. 
3. Infusoria. Ciliated forms, none of which are credited 
with serious pathogenic powers. 
4. Sporozoa, a group devoid of motile organs. To this 
sub-phylum belong the greatest number of pathogenic genera. 
It is a particularly interesting group on account of the com- 
plicated life cycle undergone by all described species, and 
owing to the necessity, in many cases, for a second host in 
which to complete development, and which acts as a reservoir 
or a transmitter for the maintenance of the race. 
Mastigophora and Sporozoa alone call for attention here : 
the more important species which are parasitic upon and 
pathogenic to domestic animals, or which have come promi- 
nently under the notice of this Laboratory, are the only ones 
which will be discussed. 
Sub-phylum, Mastigophora. Diesing. 
Class, Lissoflagellaia. 
Order, Spirochaetida. 
Genus, Spirochaeta. Ehrenberg, 1833. 
The question as to whether the Spirochaeta should be 
placed among the Bacteria in the vegetable kingdom, or in the 
Protozoa, is still discussed. At the present moment the 
consensus of opinion lies with the view that they should be 
grouped as Protozoa. 
