444 
period, we propose to call the extra-nuclear centrosomes (blepharo- 
plasts). From one or more of these granules there springs a staining 
core, or flagellum, which lies in a thin expansion of the ectosarc, 
forming the so-called undulating membrane 
For present purposes we have thus the following terminology:— 
Ectosarc = (Periplast). 
Spongioplasm == (The substance of the network of the proto¬ 
plasm). 
Cytolymph = (The substance between the meshes of the 
spongioplasm). 
Intra-nuclear centrosomes = (Karyosomes, Innenkorper). 
Extra-nuclear centrosomes = (Blepharoplasts, micro-nude; 
centrosomes, nucleoli). 
Flagellum. 
Undulating membranes. 
In none of the trypanosomes which we have studied have we 
found the slightest indication of the existence of the so-called males, 
emales, and indifferent forms. We have found that the often- 
asserted existence of these three types in the blood, a suggestion 
originating chiefly from Schaudinn* is totally misleading. 
So far as is at present known, trypanosomes are parasites 
mhab ltlngr ^ blood, and body ^ of , grea , ^ 
Hitherto no non-paras, tic forms have been discovered. As is the 
case w,th other parasites of this description, their life histories appear 
to anoth h iT Ified l ° 5feCUre their ,ransf ™ from one □ 
tissues of “ t WayS ' WHen introdu “ d into the blood and 
the noxious "nfl mU ' t 'P I >' b r *** until either 
Of some Strain! Tr !. mfeCti ° n deStro ^ host, as m the case 
runs a different °i ’ gambtense introduced into rats, or the infection 
” *> t * 
and then falls so thi i ft !” 1C b ° od nses to a first maximum, 
reappear, and reach firSt ne ^ ative Phase, the parasites 
the infection follows ^n^r^uUrTo ^ T °u In 
understoo d from the diagram given on " “ * 
Liverpool -na.fer 
see Thomas and BreinI, 
