254 Mr. H. J. Carter on Vlcesconia and Kerona. 



tion of the Ke7-07ia-cysts contained in the original one had been 

 previovisly transferred ; and the former, having been filled with 

 fresh water, was put aside for observation. 



T'or twenty-four hours after this, nothing occurred ; but at the 

 expiration of this time a few individuals of P/cesconia Charon 

 appeared, some of which were undergoing transverse fissipara- 

 tion, and in a few hours they became innumerable, — during 

 which the contents of the spherical cysts in the Kerona-cysts 

 respectively had also become active, had separated themselves 

 from their cysts, and had assumed definite forms, some having 

 escaped from the cells, while others were still rotating in them 

 rapidly, sometimes one way, sometimes the other, attended 

 by intervals of rest : with many also a lifeless portion was pre- 

 sent, which was forced round equally fast with the living one ; 

 and in several of the latter I could not only see cilia when they 

 were at rest, but, while they w^ere rotating, I thought I could 

 perceive ridges like those on the back of Plcesconia Charon. 



In this state I watched some of them, at intervals, for three 

 hours continuously, which was as much at a time as my official 

 avocations would then allow me to devote to the subject, but 

 unfortunately not sufficient for me to see any escape ; and there- 

 fore I could only infer that this had taken place from several of 

 the cells being empty and presenting a rent in one part of them 

 (fig. 11), while the group of "dark angular grains'^ outside the 

 spherical cell, but still confined within the oval cyst (fig. 11 c), 

 remained unaltered, and thus, as before stated, served as a di- 

 stinguishing mark for this cyst throughout. 



I now sought about for the Kerona, but could find none, not 

 even a single individual, and no animalcules of any consequence, 

 in this experiment, except Plcesconia Charoji, as before stated, in 

 great numbers, a few Amcebce, Vorticella microstoma, and Para- 

 mecium. 



Encapsulation of Plcesconia Charon. — The Ploesconics had not 

 appeared more than twenty-four hours when they also began to 

 assume a globular form, in the same manner as Kerona pustu- 

 lata had done — that is, by becoming shorter and shorter, and at 

 the same time secreting an albuminous substance around them, 

 within which the legs and cilia were gradually withdrawn, and 

 a spherical capsule thus formed, which adhered to the watch- 

 glass (figs. 16-18). All trace of the Plcesconics now became lost, 

 with the exception of the refractive globules common to the 

 abdominal cavity, and the contracting vesicle, which, although 

 active at first, also soon disappeared. In this passive state of 

 existence the Ploesconiae continued for two days, when the con- 

 tracting vesicle again began to resume its functions, and the 

 Plcesconia detaching itself from its capsule, began to rotate gra- 



