252 Mr. H. J. Carter on Ploesconia and Kerona. 



tain circumstances which will presently be related, they appeared 

 to issue from the capsules in the form of Plcesconia Charon ; but 

 as the series of observations is not complete, inasmuch as I did 

 not see the Ploesconia actually issue from the capsule of Kerona, 

 I shall not insist upon the fact any further than the details of 

 the experiment may seem to demand. 



Before proceeding, however, to this, it is desirable to premise 

 a short abstract of that part of M. J. Hairnets paper which more 

 particularly refers to the metamorphosis described by him, 

 in order that the reader may be able to compare the principal 

 facts contained in it with those about to be noticed by myself. 



This talented naturalist, who found the Oxyfrichaj described 

 and figured in his communication *, in the month of Septem- 

 ber 1852, in a ditch near Paris, has stated respecting its 

 encapsulation, that the process commenced by the Oxytricha 

 gradually assuming a spheroidal form by becoming shorter and 

 shorter, until at last it passed into a round ball ; that during this 

 period the cilia also gradually disappeared, so that, finally, nothing 

 but the round ball, consisting apparently of a little granular 

 matter with a contracting vesicle, seemed to remain ; that in 

 this state it continued from eight to twelve days, when some 

 small portions of its internal contents were discharged, and then 

 the rest began to separate itself from the envelope or capsule. 

 Cilia now became visible, and the portion began to rotate rapidly 

 at intervals, sometimes one way, sometimes the other. This 

 continued for several days, when the rotating mass discharged 

 another portion of its contents, which this time remained within 

 the capsule, and turned round equally rapidly with the living 

 one. The latter now began to assume the form of Trichoda 

 Lynceus, and to project a few of its cilia through the crevice in 

 the envelope formed by the discharge of the first portions of 

 superfluous material ; after this a part of the body was projected 

 through it, which remained there for a while, and was then 

 withdrawn, when the rotatory motion was again renewed ; that 

 all this was repeated several times successively, until the crevice 

 became large enough to allow the whole body to pass through 

 it, and thus the Trichoda effected its exit. 



Such is a brief summary of M. J. Haime's minute and circum- 

 stantial account of the metamorphosis, which I had hardly read 

 when a host of Keronce pvstulatce made their appearance in a 

 basin of water containing some Oscillatoria which I had under 

 observation ; and being so like his Oxytricha, and undergoing 

 similar encapsulation, I thought that they might also undergo 

 a similar metamorphosis, and therefore collected some for the 

 experiment, of which the following is a detailed account : — 

 * hoc. cit. p. 123. 



