11 



and after a careful comparison with the illustrations and descriptions furnished by 

 Holmes and Lingard already referred to, and to which they appeared identical, he wa3 

 inclined to consider them as developmental forms of trypanosomata. But subse- 

 quently, when positively no difference could be detected between these forms and 

 certain of the spores of Sarcocystis isolated from cases I. to VIII. and case XII., he 

 (the writer) became convinced that they belong to the latter genus of a parasite, and 

 excludes any relationship Detween these crescents and trypanosomata. Certainly, such 

 forms of the spores of Sarcocystis as are here depicted, Plate II., fig. 5, Nos. 2 and 6 

 and some others, may very easily be mistaken for trypanosomes in which the flagella 

 and undulating membrane have been cast off, for ' stumpy,' swollen forms. It is 

 of great importance, therefore, in diagnosing such a serious infection as Trypanoso- 

 miasis from Hood specimens to remember the possibility of the presence of Sarcospori- 

 dia and their likeness to questionable forms of trypanosomata. 



Conclusions. 



1. The parasite Sarcocystis under certain conditions becomes a very important 

 factor in disease, invading the entire musculature of their hosts, with serious or fatal 

 consequences. 



2. Sarcosporidiosis may be closely associated with, and is probably a very frequent 

 sequel to, the disease of horses and cattle known as ' Loco-disease.' It may complicate 

 the diagnosis of this disease, and also of Dourine, and probably of some others, and 

 retard or prevent recovery from these and similar cachectic conditions. 



3. The crescentic spores of Sarcocystis bear a striking resemblance to ' Cresentic- 

 bodies' that have been described as developmental forms of trypanosomata, and it 

 would be unsafe, or quite erroneous to diagnose an infection by the latter from the 

 presence alone of those crescentic bodies. 



4. The Sarcosporidiae are deserving of more detail study and investigation than 

 has hitherto been accorded them, both from a zoological and a pathological standpoint. 



EXPLANATION OF PLATES. 



Plate I. 



Fig. 1. — Cross-section of bundle of muscle fibres infected with Sarcocysts (from 

 splenius muscle of heifer, Case II., hematoxylin and picric acid. Leitz objective 

 No. 3 Ocular No. 3. 



Fig. 2. — Longitudinal section of the same. 



Fig. 3. — Young parasites showing radially striated envelope, and pansporoblasts 

 from flexor metacarpi externus muscle of a horse, Case III. Objective No. 6, Ocular 

 No. 3. 



Plate II. 



Showing the spores of Sarcocystis, A oil immersion, ocular No. 3. 



Fig. 1. — Variations in size, shape nuclear arrangement, and formation of polar 

 capsule. 



Fig. 2. — Nos. 1-4, and fig. 3, Nos. 1-3. Dividing forms. Note the centrosomes in 

 fig. 3, No. 1. 



Fig. 3. No. 5. — Gametes or Zygote formation (?). 



Fig. 3. No. 6. — An example of spores more lightly stained, and showing only the 

 position of the polar capsule. 



