10 



in the arrangement of their chromatin and polar capsule. In form they appear in all 

 gradations from a perfect sphere to an oval, bean-shaped or crescent form, though 

 each type is symmetrical and doubtless represents different stages in the development 

 of the spore-cell. The spherical forms would appear to be the younger and the cres- 

 centic the older, as in each trophozoite containing many spores, some are found dis- 

 integrating and these are almost invariably of a crescentic variety. 



The chromatin granules of the nucleus of the spherical spore are relatively small 

 and scattered, and the polar capsule is granular and only partially developed; in 

 the next stages, the chromatin collects into small bodies, and one end of the cell 

 becomes pointed, and at this end is always found the polar capsule. This capsule 

 stains with difficulty with most dyes, and not at all with the ordinary basic 

 stains; even with some of the Eomanowsky preparations only a faint pink ectoplast 

 at one end of the spore, and where the protoplasm has receded, denotes the position 

 of the capsule (see Plate II., fig. 3, No. 6). The Eomanowsky stains, however, are 

 preferable to any other, and, properly prepared, differentiate very clearly and beauti- 

 fully the structures of the cell. A single granule, staining black, and, more rarely a 

 double granule, may occasionally be seen, situated about half-way between the nucleus 

 and the pointed extremity; this is doubtless the centrosome. (Plate II., fig. 7 — the 

 end spore, fig. 3, Nos. 1 and 6). In the older spores the nuclear chromatin collects 

 into round or irregular bodies, eight to sixteen in number. The frequent finding of 

 a large spherical spore and a crescent lying intimately, and in some cases apparently 

 fused, together, is suggestive that the former is the female cell and the latter the 

 male gamete (Plate II., fig. 3, No. 5). A large spherical form, probably resulting 

 from the fusion, of these two elements, may be seen dividing directly into two, three 

 or four. (Plate II., figs. 2 and 3). 



The possibility of mistaking the spores of Sarcocystis for developmental forms of 



Trypanosomata. 



From time to time mention is made by various workers, of large ' crescentic 

 bodies ' or ' vermicule-like forms ' occurring in the blood of animals affected with 

 trypanosomiasis, and are generally described as developmental stages in the life- 

 history of a species of trypanosomata. 



Holmes, in an article entitled ' Trypanosomiasis among cattle in India,' states, 

 ' In the blood taken from two infected bulls I found peculiar developing forms bear- 

 ing a striking resemblance to the crescents of human tertian fever. These are large 

 crescent-shaped bodies staining blue and containing numerous chromatin granules.' 

 Some of these forms of trypanosomata ( ?) are illustrated by autnor. 



Lingard 6 in ' Species of trypanosomata observed in Bovines in India ' mentions 

 the above observations of Holmes, and further describes similar forms met with by 

 him (Lingard), also illustrating them in coloured plates (Plate II., fig. 20, and Plate 

 III., fig. 7, Journal Tropical /et. Science, Vol. II., No. 7, 1907), stating ' These cres- 

 cent forms, above described, are frequently co-existent with the piroplasma bigeminum 

 or the smaller forms in the blood of Indian cattle, irossibly the presence of the cres- 

 cents in Queensland bovines may point to the fact that these animals in some instances 

 are also the host of a large form of trypanosoma, which up to the present has not been 

 demonstrated in their blood.' Hunt, quoted by Minchin (page 26-9)' and also by 

 Lingard, ' found crescents in the blood of cattle, and observed their change into a 

 spheriodical shape, but while comparing these bodies to the crescents of malarial 

 parasites, he at the same time regards them as a form of sporulating body, producing 

 spores endogenously.' Martin in criticizing the observations of Holmes states 

 'Eaymond also afterwards found them {i.e., the crescents) in the cattle of Bengal, 

 and he is inclined to the opinion that they have nothing to do either with trypanoso- 

 miasis or piroplasmosis, but that they are really Sarcosporidia.' The writer ventures 

 to express a similar opinion. At first, in finding them in the cutaneous swellings of 

 Dourine-affected equines, side by side with mature and unmistakable trypanosomes, 



