212 COCCIDIUM OVIFORME. 



jurious effect on them. Indeed, it has been stated that their de- 

 velopment proceeds more rapidly in these solutions than in water, 

 but this certainly seems to me to require further corroboration. 



Whether it be by chance or not, the shortest period of incubation 

 has been as yet exclusively observed in intestinal Coccidia. Walden- 

 burg, in the later experiments which he made with hepatic Coccidia, 

 was, like the others, unable to observe further development till after 

 the lapse of weeks or months. He thinks it possible that the chromic 

 solution with which he treated his objects might possibly penetrate 

 the intestinal walls more easily and more thoroughly than the masses 

 of liver; but the insufficiency of this explanation was shown by the 

 fact that isolated hepatic Coccidia, though far more accessible to ex- 

 ternal influences than the Coccidia of the intestinal epithelium or 

 Lieberkiihnian glands, yet required hardly any shorter time for their 

 development. 



The changes which occur in the free-living Coccidia (Fig. Ill) are 

 concerned, as we have previously noted, with the production of spores 

 the only structures which we can compare with the Psorosperms of 

 allied organisms, and which we might designate by the same name 

 if we wished to use the word in connection with Coccidia. Kauff- 

 mann declares that these Psorosperms agree with the parent Coccidia 

 in everything but size ; but Lieberkiihn has already justly condemned 

 this statement. The Psorosperms are not only much smaller (0'012 

 mm.) than the Coccidia, but are in their organization hardly less 

 divergent than is the case in the other Sporozoa. The insufficient 

 microscopic power used must certainly be to blame for Kauffmann's 

 mistake. 



He has, on the other hand, observed with perfect accuracy that 

 the spores originate by division of the central granular mass. It only 

 rarely happens, indeed, that the actual division x is seen, but that only 

 proves that it takes place with great rapidity. In the cases I have 

 observed the four parts can always be distinguished 2 in the granular 

 ball, even when this is still a coherent mass ; so that I must leave it 

 undetermined whether a division into two first occurs, or whether the 

 four spheres are present from the beginning. Along with the granular 

 mass the clear plasma inside also divides, so that at the close of the 

 process four segmentations-pheres are found inside the shell, which 

 differ (Fig. Ill) from the former central mass in their smaller size 

 (0-009 to 0-01 mm.). 



1 Waldenburg says he has sometimes observed this segmentation while the Psoro- 

 spermice were yet in the liver. 



2 I have always found four segmentation spheres and four Psorosperms, never more 

 nor less, although many observers report two or three. Cases of an apparently smaller num- 

 ber are always optical illusions, in which two Psorosperms lie upon and obscure one another. 



