216 COCCIDIUM OVIFOKMK. 



with four nuclei arranged crosswise, and containing a granular mass, 

 which lies embedded between the nuclei, and gathers itself around 

 them. Finally, in the last stage of this developmental process Wal- 

 denburg observed that the individual segmentation-spheres had each 

 divided into four new spheres, which enclosed a clear nucleus, and 

 had quite the same appearance as the original spheres, though of 

 course smaller. Thus the Coccidia contained sixteen small indepen- 

 dent bodies, which had resulted from a repetition of the division of 

 the original contents into four. 



In these bodies Waldenburg thinks he has at last found the 

 true germs of the Coccidia. They still partially cohere in fours, 

 and issuing from the micropyle, or from an accidental breach, they 

 exactly resemble in action and appearance certain bodies which 

 originate in great number in the liver-cysts, and which he regards 

 as the youngest stage of the Coccidia. The bodies under dis- 

 cussion are described as about the size of a red blood corpuscle, some- 

 times larger or smaller, some spherical, others oval, some elliptical, 

 others sickle-shaped, and occasionally even provided with fine pro- 

 cesses. A distinct membrane is not visible, but a nucleus is usually 

 quite distinct. Waldenburg believed he could observe an "apparently" 

 active, " at any rate not wholly " passive movement, and felt warranted 

 in regarding them as amcjeboid organisms. 



Nor is Waldenburg the only one who maintains the further de- 

 velopment of the four parts. Kivolta also reports similar processes, 

 but he supposes that the parts do not segment afresh, but gradually 

 form internally, at the expense of the granular mass, two, three, or 

 four shining bodies, which represent the germs (" micrococchi psoro- 

 spermici"). They possess great power of resistance to external in- 

 fluences, and can even survive desiccation. In the first reports (1869) 

 these germs, and even the segmentation spheres, were credited with 

 cilia, and regarded as Infusoria. 



I cannot deny that really observed states lie at the foundation of 

 these representations ; nevertheless, I cannot regard the changes which 

 they exhibit as normal stages in the development of the parasites, but 

 consider them simply as the phenomena of a dissolution which takes 

 place in old infusions, as above indicated. The spores change their 

 earlier ovoid form for a rounder one, the rod inside becomes indistinct, 

 the shining heads become displaced and disjointed, or the whole rod 

 may fall into pieces, while the granular mass becomes inflated, and 

 the granules flow together into coarser grains ; a series of deceptive 

 appearances thus originating to which the influence of a fixed idea 

 easily lends an undue importance. 



Even in Lieberkuhn's researches we find figures which exhibit such 



