SARCOSPORIDIA. 203 



showed two spores in the spleen smear. In muscle blood smears 

 from 100 carcases (cattle and sheep that died at Armoedsvlakte ) 

 -|0 per cent, showed either sarcocysts or sporozoites, or Iwth. 



McGowan states that nothing of the nature of a sarcocyst, 

 spore, or a possible derivative from such was ever seen in the 

 l)]<)()d of shoe]) suffering' from scritf^ic. 



Morphology. 



As a rule the Sarcosporidia appear to l)e harmless j.arasites 

 which do not make their presence known by any s}-m])t()m> of 

 disease, and can only be detected by post-mortem examination, 

 and often onl}' l)y histological examination. The sarcocysts 

 may present themselves as opaque whitish bodies, usually elon- 

 gated and cylindrical in form, their long axis running with llie 

 long axis of the muscle, enc)'sted in the infected animal, and 

 known commonlv as Fleischer's tubes. They may be distinctly 

 visible to the naked eye. and often very large. Sarcocysts in 

 sheep reach a length of 16 m.m.. while in the roebuck cysts of 

 50 m.m. in length are recorded. According to some the cysts 

 are yellowish-Avhite in colour, and may varv in size from a millet 

 seed to a hazel nut. with a pus-like contents. Sarcocysts of 

 the mouse, according to Blanchard. is only in the mature state 

 visible to the naked e}e. when it appears as whitish streaks 

 running parallel to the fibres of the voluntary muscles. When 

 teased out of the fresh tissue, these streaks resolve themselves 

 into opaque, thin-walled tul)es, densely packed with crescentic 

 bodies, the so-called sjjoroznites. Balfour in 1012. in the 

 Gasella ntfifrons. described the ATeiscber's tubes as possessed of 

 a fairly thick cuticle ; they measured on an average 4 m.m. in 

 length, and contained the usual sjiorozoites lying in a milk-white 

 and cheesy medium, which could he easily smeared on a slide, 

 and contained what looked like minute crvstals. The Sarco- 

 sj/oridia encountered in certain cattle that had died of lauLciekte 

 and in the sheep that had died of poverty at Armoedsvlakte were 

 not recognisable macroscopically ; cysts as described above were 

 not seen. The Professor gives the size of the very small tubes 

 as 40-68 /u in length ;uul 10-20 /a in breadth. These figures 

 taliate more or less with those of the sarcocysts seen in the 

 muscles of shee]i at .\rmoedsvlakte. Under a higher ])o\vor Sar- 

 cosjwridia appear to be bodies of a complex structure whh a 

 granular ap])earance. The latter is due to vast nmnbers of 

 crescentic-sha])e(l bodies, the so-called sj^ores. sporozoites, sickles, 

 or Rainey's cor])Uscles. lying in clumps or bunches contained in 

 small oval chambers. The chambers are separated from one 

 another by ])artitions. which are contiguous with the enveloiie, 

 which surrounds the Avhole organism. The membrane enclosing 

 the tubes is at first a fine, structureless cuticle, but before long 

 it thickens and becomes channelled by mimerous fine canaliculi 

 arranged for the most part transversely to the long axis of the 

 parasite, but towards the extrenuties directed obliquely, and at 



