E911. | Trypanosoma gambiense 7m Glossina palpalis. 515 
TYPES OF TRYPANOSOMA GAMBIENSE FOUND IN THE ALIMENTARY CANAL. 
It would serve no good purpose to describe separately, day by day, the 
types found in the various parts of the alimentary canal, as they run into 
each other in such a way that any classification of them seems impossible. 
The following table represents, approximately, the numbers found in the 
different parts of the alimentary canal at various times after infection, The 
— sign means that an examination was made and nothing found. + means 
few. +,many. + +,very many. + + +,swarming. If no sign, then 
no examination has been made. (See p. 516.) 
The Proboscis.—In our experience Trypanosoma gambiense is never found in 
the proboscis of Glossina palpalis, except immediately after an infected feed, 
when for a short time blood containing trypanosomes may be seen in the 
lumen of the proboscis. This is very different from what obtains in an 
infection by 7Trypanosoma vivax, in which case the proboscis is alone infected. 
Proventriculus.—As seen from the above table, this part of the alimentary 
canal is sometimes found empty when the remainder of the gut is swarming. 
Fore-, Mid-, and Hind-gut.—It is here that the greatest development of 
the trypanosomes is found. Among the extraordinary numbers and diversity 
of type it is difficult or impossible to find one’s way. Generally speaking, the 
trypanosomes found during the first few days are merely degenerating blood 
forms. After this there appears a type of trypanosome which remains 
dominant throughout the whole developmental period. This is a long, 
moderately broad form, the protoplasm staining well, without granules or 
vacuoles, having an oval compact nucleus situated in the centre of the body, 
a small round micronucleus lying at some distance from the elongated snout- 
like posterior extremity, the undulating membrane narrow and simple, and 
the flagellum proceeding little, if anything, beyond the protoplasm of the 
cell. The flagellum also appears very frequently to arise from a pink- 
coloured body situated near the micronucleus, an appearance never seen in 
_the normal blood trypanosomes. 
This seems to be the healthy normal developing type in the intestine of the 
fly. [tis seen in all parts of the intestine and at all times. It forms masses 
of innumerable individuals alike in size and shape. When a fresh supply of 
blood is taken in by the fly this type can be imagined to multiply with 
extraordinary rapidity. When the blood supply runs low then this type 
can also be imagined as degenerating and disappearing just as rapidly. The 
host of diverse forms which thus arises beggars description. Some are 
round or oval in shape, 3 or 4 microns in diameter, with or without 
a flagellum. From this simple form all shapes and sizes can be seen up to 
the huge shapeless mass of protoplasm, multi-nucleated and multi-flagellated. 
