TRYPANOSOMIASIS EXPEDITION TO SENEGAMBIA 53 
about 28 m from the posterior end ; it is finely granular, is coloured light crimson, 
and extends completely across the short axis of the parasite. The micronucleus is in 
close proximity to the macronucleus, though separated by a slight interval. Its 
position on an average is 26 ,u from the posterior end of the organism. It stains a 
deep crimson, is devoid of structure, and is surrounded by a zone staining light 
blue. The average length of a parasite as measured in stained preparations is 72 fx- 
This excludes the tree flagellum, which is from 10 /< to 1 5 //. long. The width of the 
parasite at the macronucleus is 8 /x- 
The frog infected was eventually killed, and preparations of blood taken from 
various parts of the body were examined. Parasites were seen in all, and were not 
found to be particularly numerous in the preparations from any one organ. No forms 
were seen in developmental stages. No parasites were seen in the peritoneal fluid. 
The organs of the frog appeared normal macroscopically. 
Trypanosoma Karyozeukton. — New species (provisional). 
In a stained (Romanowsky) preparation of the blood of a frog (sp. ?) 
caught at Cape St. Mary, Gambia, October 23, in a fresh preparation of which T. 
sanguinis had been seen, one specimen of a large trypanosome (Plate II, fig. 5) was 
encountered presenting the following characteristics. 
Length, excluding the flagellum, 67*2 p. Width at macronucleus, 6*4 fx. 
Distance from micronucleus to centre of macronucleus, about 16^. Distance 
from micronucleus to posterior extremity, 9/8 m. Length of free flagellum, 15*2 /u. 
As in the preceding trypanosome, the body protoplasm posterior to the 
macronucleus presents a contrast to the anterior portion. The former does not 
stain so deeply and has a mottled appearance. The latter stains more deeply, has a 
much more closely arranged spongioplasm, and in it faint longitudinal striation can 
be made out. The micronucleus is ovoid, stains a dark crimson, and shows no 
structure. The macronucleus extends the whole width of the organism and takes 
on a light crimson colour. Its structure cannot be made out. Posterior to the 
macronucleus are scattered, for a short distance in the protoplasm, fairly large 
granules, staining a deep bluish-purple colour. Between the micronucleus and 
macronucleus runs a chain of small red oval granules, which are, apparently, of the 
same nature as chromatin. Examination with a — /; oil immersion has not enabled us 
12 
to say definitely that there is a union between the macronucleus and micronucleus 
by means of this chain of chromatinic granules. The posterior end of the parasite 
gradually tapers to a fine filament. Posterior to the micronucleus the narrowing 
becomes more marked. The undulating membrane commences opposite the 
micronucleus and runs along one side of the organism as a narrow band. It is 
stained faintly pink. 
Three other frogs were received at the same time as that which harboured 
the trypanosome just described ; in the blood of two of these were seen an 
