— 10 — 



into groups in the sacs is not to be found in the species 

 described. In connection with this is the absence of the sys- 

 tem of strands of the basal substance by means of whicli 

 in many Sarcosporidia the contents of the sac are divided 

 into chambers. In this respect S. hubalis resembles the 

 species aS. lindemanni (Rivolta) and *S. muris B Ian chard, 

 in whicli the strands named are weakly developed and are 

 very thin and tender. 



Being imbedded in the muscle-fibres the sacs of -S. hubalis 

 follow all the changes in the form of the muscle -fibre. In 

 the cases, when the muscle cell contracts and is covered 

 with undulated folds, we find corresponding folds on the sac 

 of Sarcocijstis (fig. 3) as well. The structure of the mem- 

 brane— which I succeeded in revealing pretty well — also deserves 

 attention. Notwithstanding the many works relating to Sar- 

 cosporidia, the question of the structure of their membrane 

 -has not yet been solved. For instance, even in the latest edi- 

 tion (1911) of Doflein's large text-book on Protistology it 

 is said that the exterior layer of the membrane of Sarcospo- 

 ridia „ consists of numerous parallel rods set perpendicularly 

 to the surface of the body, or, it may be more correctly, the 

 membrane is pierced by numerous canals, which in section 

 give the appearance of striation or of a ciliated tegument". 



Since the book quoted was published, there have not appeared 

 any new data concerning the structure of the membrane in 

 Sarcosporidia. 



On account of my own investigations on S. hubalis I 

 can positively affirm that the first point of view is more 

 correct, and that porosity of the membrane in Sarcosporidia 

 is to be denied. The exterior membrane of Sarcocystis consists 

 of rods, or rhombic prisms arranged in definite order, namely, 

 iQ diagonal rows with respect to the long axis of the sac. 

 The arrangement of the prisms mentioned is best seen on 

 superficial longitudinal sections through the sac. Thus, fig. A on 

 the page 5 represents a superficial section that has passed some- 

 what obliquely through the sac of S. hubalis; in the upper part 

 of the drawing the. section passes through the sac itself filled 

 with spores and surrounded by a striated membrane; in the 

 lower part of the drawing the section passes only through the 

 exterior membrane of the sac, the rods of which are cut 

 transversely. The arrangement of the rods in diagonal rows 



