A. C. Coles 
0*5, 
Degenerate Trypanosomes. In the blood of moles that had been 
dead some hours I not infrequently met with structures which were 
obviously remains of trypanosomes. These bodies were round, trans¬ 
parent structures staining very faintly with Giemsa, and containing 
a few chromatoid granules. Towards the margin one could make out 
a part faintly coloured red, and at times a spot representing a centrosome, 
whilst in a few distinct signs of a flagellum were present. It seemed as 
if the trypanosome had rolled itself up into a ball or had become swollen 
into a cyst-like body. 
Trypanosoma lewisi. 
The number of rats {Miis decumanus) found infected varies con¬ 
siderably in this locality, but I should expect to find trypanosomes in 
the blood of one or two out of five fully grown rats. I have thought 
that the parasites were not .so frequently present in young rats. 
(Plate II, fig. 7.) 
The form of T. lewisi found is very constant, although I have noticed 
that in one case, a rat which was also infected with haemogregarines, 
all the trypanosomes wei’e larger than usual. 
I have examined the blood of a very large number in an endeavour 
to find developmental forms in the naturally infected common rat, but 
have entirely failed. 
I have nothing to add to the well known description of this 
trypanosome, except that in well but perhaps lightly stained preparations 
the centrosome almost invariably shows a line through the centre, thus 
II. My friend Mr E. M. Nelson first pointed this out to me. It is by 
no means peculiar to T. lewisi but is seen in many species. It requires 
a good lens, critical illumination and above all a trained eye to detect it. 
Pulmonary Cysts in the Rat. 
In smears of the lung taken from a veiy large rat whicli had been 
much mauled by a dog, I found small bodies about the size of a red 
corpuscle, containing eight blue stained small merozoites or vermicides. 
They were very infrequent, not more than 20 being found on a ^inch 
coverglass. (Plate II, figs. 12 and 13.) 
They are generally round, sometimes oval, rarely pear-shaped, and 
stain a pale blue colour with Giemsa. They varied in size but on 
an average measured .5 to 6 /a in diameter. Each cyst contained eight 
small bodies which stained a deep blue colour with Giemsa, and had 
