A. C. Coles 
185 
Figs. 1 to 12 were found in smears of the lung of a small rat (A), 
killed 10. xn. 1913. 
Fig. 14 (x 2000), was from lung smear of Rat B, 20. viii. 1914, and 
shows very clearly the size of the larger of these bodies compared with 
an ordinary trypanosome. 
Trypanosomes do not always when coiled up assume a round form, 
one not infrequently meets with structures resembling a figure of oo , 
or even a narrow elongated body. 
Figs. 9 to 12 show structures found in lung smears of Rat A, as to 
the nature of which I am in doubt. 
Fig. 9 is almost certainly a coiled up trypanosome in which a nucleus 
and a centrosome are seen. Figs. 10 and 12 are probably of the same 
nature, whilst Fig. 11 may be a diatom. I have certainly met with 
definite diatoms in the lung smears of rats. 
PI. XI, figs. 18 and 19 (x 2000) were found in the lung of a Rat C, 
1914. They were associated with the presence of a few coiled up trypano¬ 
somes. They are irregularly oval bodies, the outer part of which seems 
to be a dense capsule which stains a deep red colour with Giemsa, and 
contains a faintly blue stained structure bent upon itself. This internal 
body contains evidences of a nucleus or nuclei and a centrosome, especially 
Fig. 18. I think there is little doubt that this represents one or two 
trypanosomes encysted. I thought at first sight that they were a 
trypanosome coiled up in a red blood corpuscle, but the surrounding 
part is stained very unlike the colour which the haemoglobin of the 
red cell takes on. I failed to find any more of these bodies in any of 
the films. 
Minute Trypanosomes. In the lung smear of Rat A, in addition to 
the coiled up trypanosomes and the diatom-like bodies, I found a 
small group of four minute but distinct trypanosomes, each of which 
had a nucleus and a centrosome, but no flagella could be detected. 
These are shown in Fig. 5 (x 1500) and Fig. 13 (x 2000). I searched 
this film very thoroughly but could find no other example, nor could 
I detect any of Carini’s Pulmonary Cysts. 
What is the nature and origin of this little group? They are not 
at all like the merozoites of the Pneumocvsts of Carini, and no examples 
of these bodies in any of their stages were found in this specimen. 
My impression is that they originated from a Leishmania sphere, as 
is shown in Fig. 16, although I could find no evidence of this in the 
preparation. 
Pulmonary Cysts in the Rat. I have described these more fully 
