250 TRANSACTIONS OF THE CANADIAN INSTITUTE. [VoL. I. 



If the determination of the division of the nucleus is difficult, much 

 more so is that of the full history of the spores. They are so small at 

 first that, apart from the mother organism, they cannot be distinguished 

 from other cellular contents, such as the swallowed portions of the 

 debris of neighboring cells and the spore stages of other parasites. It is 

 only in a few cases that circumstances favor the determination of some 

 of the forms after they have escaped. In Fig. i, for example, is 

 shown a cavity in the interior of a cell, evidently once occupied by the 

 parasite in question, and in the neighborhood of the cavity is a number of 

 bodies like plasmosomata, of similar, or nearly similar size. These are 

 evidently the spores derived from the organism which occupied the 

 cavity. In a few instances, with the best conditions for observation, forms, 

 like those shown in Fig. ^a, are seen. Here the structures are comma- 

 shaped, and their resemblance to other forms in the same Figure, to that 

 of Fig. \oa and to those in Fig. 2, is such as to suggest a developmental 

 relationship. The probability, however, that very young forms of Sporo- 

 zoan parasites are similar to those represented in Fig. ga, is sufficient to 

 invalidate any conclusion that might be drawn from this resemblance.* 



There is more certainty in regard to the larger comma-shaped forms, 

 such as are shown in Figs. 2 and \oa. These are intensely safranophilous 

 bodies, and measure from 3 to 6/x. Their outlines are sometimes distinct, 

 sometimes not, this depending on the way in which the organism is dis- 

 posed in the field of the microscope. If the tail should happen to be above 

 or below the head of the comma the organism may be recognised with 

 difficulty. The connection between these and the spherulating forms can 

 be seen by glancing at Fig. 10 a-Ji. In further development the head of 

 the comma enlarges, the safranophilous substance collects into a small 

 round mass, leaving the protoplasm which contained it more or less 

 coarsely reticulated or finely granular, and with feeble staining capacity. 

 The tail still retains its safranophilous character and remains distinct 

 for several stages. The space between it and the head tends to increase 

 when its point becomes applied to the head (Fig. 10^). At the same 

 time it becomes somewhat elongated (^), and the safranophilous sub- 

 stance in it condenses into a thin band bounding the convex side of the 

 crescentic cavity. The head also undergoes further changes ie). The 

 protoplasm becomes collected at its periphery as a rim to which the small 

 round safranophilous mass, the nucleus, is attached by delicate proto- 

 plasmic strands. In the next stage protoplasmic strands may stretch 

 across the crescentic cavity, to the remains of the tail or the point of the 



*Compare with Steinhaus' Figures of the intracellular parasites in the pancreas of the Sala- 

 mander, Ziegler's Beitrage Zur Path. Anat., Bd. VII., Taf. XI. 



