220 
the subsequent formation of a flagellum, and the assumption of 
" herpetomonas-like " characters described by Koch (their occurrence 
seems most probable). 34 
The spherical forms are produced in Glossina in the same way as 
in the rat flea (see below). The independent movements of flagellum 
and cytoplasm are most striking in parasites in the process of exflagel¬ 
lation. When separated the flagellum and blepharoplast quickly 
become motionless ; the cytoplasm is mobile for a little longer. These 
rounded forms were not seen to divide, but from the analogy of 
Trypanosoma loricatum? 4 and from the difference in size between 
the smallest rounded forms (4*5by 3*75/1) and the average pear- 
shaped trypanosome (8‘o/i by 5*0/1) just before ex flagellation is 
complete, it seems possible that they may do so at this stage. After 
the flagellum and blepharoplast are cast off, the nucleus, at all events 
in some cases, fragments into from eight to ten granules. These 
then collect together to form a new central mass (some may remain in 
the cytoplasm ; are any extruded ?). Before the motor apparatus is 
thrown off from the rounded trypanosome it sometimes circumscribes 
the parasite so as to simulate a cyst wall no real encystation has been 
observed. (Moore and Breinl 26 describe the formation of a cyst wall 
in similarly rounded parasites observed in trypanosome-infected 
animals treated by atoxyl.) 
II. IN PED1CULUS 
In July and August, 1903, a few pediculi caught on a rat very 
heavily infected with 7 rypanosoma gambiense were dissected and 
examined fresh at room temperature. Granular, indistinct, obviously 
exonerating P arasi I es were of course present. The main change 
seen in those apparently normal was the formation of ovoid or 
spherical trypanosomes (5-6/1 by 6-4/1 to 8-32/1 by 7-6/1). These had 
stained specimens the same appearance as those observed u> 
trypanosomes from the gut of tsetse flies. The following short 
one observation sufficiently describes what was seen > n 
caught lousp . r “ t * fiIled wit h bright red blood, was drawn from a fre 
active normal . Was 1 en tease< I out in a minute drop of normal saline. 
stumpy forms Wer ® P resent - All were long and large at first 
later the normal na - Some of the parasites were quite granular. One 
present which haH w* ^ ® l6SS num erous, and pear-shaped trypanosomes ’ 
to which the flal n Undulatln S membrane and flagellum. Similar forms exi 
* flagellUm was s *ill attached by the blepharoplast. In these fc 
