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



from their own cysts, on the other, wliich were mixed up with 

 the Kerona-cysts when the latter were transferred to the watch- 

 glass, and whose contents, as a matter of course, became equally 

 active with those of the Kerona-cysts on the addition of the 

 nutriment to the water in which they were contained. The 

 absence of the Kerona, therefore, is no proof of the metamor- 

 phosis. 



Secondly, the cyst of M. J. Haime^s Oxytricha and that of 

 Kerona pustulata are quite different (as may be seen from our 

 drawings respectively), while the former clearly approaches that 

 of Ploesconia Charon, wliich being intimately allied to Trichoda 

 Lynceus in every respect, leads to the infei-ence that the cysts of 

 Trichoda were also in M. Haime's case mixed up with those of 

 Oxytricha, and that he mistook the former for the latter, which 

 thus led to the conclusion that Oxytricha had undergone meta- 

 morphosis into Trichoda. Again, the resemblance between his 

 Oxytricha and Kerona 'pustulata is so great, that one would 

 think that they should be equally alike when encapsuled, which 

 not being the case, still further supports the supposition that 

 the capsule from which Trichoda Lynceus issued was not that 

 of Oxytricha, but its own capsule. 



Lastly, in my own case, the direct ovular-like origin of 

 P. Charon, from its extreme smallness on some occasions, is, as 

 before stated, opposed to the view of metamorphosis, in which 

 such a diminution in size could hardly ever occur. Latterly 

 I have had a host of Keronce pustulatce, obtained from the 

 source above-mentioned, among which there was not a single 

 Ploesconia of any kind to be seen, from the 1st November 1853, 

 when the water containing them was transferred from the main 

 drain of the island of Bombay to the basin for observation, up 

 to the 28th, when almost all animalcular life in it had ceased 

 to exist. Although during this time the Keronce had been 

 nourished with glue so successfully that they not only attained 

 their full development, but multiplied themselves to an incalcu- 

 lable degree by fissiparation and budding, and in many instances 

 presented the early stages — viz. the shortening, &c. — of encapsu- 

 lation, which may reasonably be inferred to have been com- 

 pleted, though I did not meet with any of the cysts — thus 

 arriving at the state which must have led to metamorphosis, 

 under the continued nourishment that w^as afforded them, long 

 before this was withdrawn, — yet not a single Ploesconia of any 

 kind was observed among this group throughout the whole ex- 

 periment. 



All things considered, then, the above statements rather throw 

 a doubt over, than confirm, the conclusions of M. J. Haime re- 

 specting the metamorphosis of Oxijtricha into Trichoda Lynceus. 



