A. C. Coles 
27 
The protoplasm stains a faint blue colour, has a loose granular 
appearance, but possesses no evidence of myonemes. Irregularly shaped 
vacuoles may be seen in the protoplasm. The centrosome is either 
round or rod-shaped. The attached portion of the flagellum traverses 
the body obliquely two or three times in its course. 
The free flagellum is longer than in the fusiform t^pe, genei’ally 
measuring about 7 jx, and is about one third the length of the body. The 
nucleus differs considerably from that found in the fusiform type. It is 
generally oval with its long axis at right angles to that of the parasite, 
and measures about 7 /x in length and 2’8 /x in breadth. It is almost 
invariably surrounded by a halo of unstained cytoplasm. In structure 
it is seen to consist of a peripheral layer of closely packed granules 
with a central fainter granular area. 
As to the proportion of the two types of trypanosomes I found that 
of 12G parasites 56 were fusiform and 70 piriform in shape. 
Subsequently I found the large fusiform trypanosomes in a black¬ 
bird on April 28,1912, associated with Halteridia, and in a young black¬ 
bird on May 16, 1913, in conjunction with Halteridia and Leiicocytozoon, 
but in both cases the trypanosomes were present in exceedingly small 
numbers, perhaps one being found in five or six films. 
Small Trypanosomes of the Thruslr 
In the blood of an apparently healthy thrush shot Aug. 29, 1911, 
I found the following parasites: 1. Proteosoma, very numerous. 
2. Trypanosoma, small, fairly numerous, and two large forms. 3. Leuco- 
cytozoa, small infection, with forms of schizogony in the peripheral, 
heart and lung blood. 4. Halteridia, few, and 5th Filaria, embryos 
numerous. 
As to an approximate number of trypanosomes: 21 films were 
made, 12 from the axillary vessels, eight from the blood of the heart, 
one from the lung. Over an area of a | inch coverglass 91 trypanosomes 
were found in 18 films, three films were negative as regards trypanosomes, 
so that the average number found on a single film would be about 
4^. The largest number found on a single film was 26, this preparation 
was made from the heart about two hours after death. I should add 
that of the three slides which proved to be negative, two were fixed 
whilst moist with Schaudiun’s sublimate mixture and stained with 
Heidenhain’s iron-haematoxylin. 
As these parasites belong to the small variety of trypano.some, and as 
they did not take on the basic blue colour of Giemsa or Leishman’s 
