[ 394 ] 



Some ifurtber IRescarcbee of 

 • pyot ]£. 6. Balbiani on tbe flDerotom^ 

 of Ciliateb 3nfu6onan6** 



By F. Vicentini, M.D., Chieti, Italy. 



IN a former number (see p. 202) we gave an abstract of the 

 interesting discoveries of Prof. Balbiani on the Merotomy 

 of Ciliated Infusorians ; these referred chiefly to Stefitor 

 ccBruleus, and were published in the Annales de Micrographie 

 for 1892. In the January number of the same work, for 

 the current year (1893), he followed up the subject by new re- 

 searches on other species of Ciliata, the results of which, together 

 with his views in reference to general cytology, we summarise as 

 follows : — A, The Merotomy of Stentor polymorp/ms, Stentor ig?ieus, 

 Dileptus aftser, Loxodes rostrum^ and Fabrea saliiia ; B, The 

 Merotomy of Paramceciiwi aui-elia, ParamcEciiim bursaria, and 

 Colpidium ; C, Prof. Balbiani's general views in reference to 

 cytology ; and Z>, his general conclusions. 



A. — The author summarises his experiments on Stentor poly- 

 morphus^ Stentor igfieus, Dileptus anser, Loxodes rostrum, and 

 Fabrea salma, in the following manner : — 



I. — vS. polymorphus and ^. igneus exhibit, when divided by 

 merotomy, the same phenomena as does S. ccsruleus (see p. 202), 

 only those fragments which contain a nucleus are capable of regen- 

 eration, whilst those which do not contain a portion of nucleus die 

 in a few days 



2. — Some individuals of S. polymorphus, which have a normal 

 and healthy appearance, have, at the same time, the nucleus 

 entirely invaded by a parasite {Holospora obtusa). Their survival 

 can only be accounted for by supposing that a small portion of 

 nuclear matter still remains in the nucleus. 



3. — In Dileptus anser (a mono-nuclear species with a diffuse 

 nucleus, and the nuclear matter dispersed in the plasm Uke minute 

 granules) all the fragments have the power of regeneration, which 

 takes place rapidly (in about four hours), and the regenerated 

 fragments will live for several weeks on the slide like normal 



individuals. 



* Annates de Mio'ogmphie, Vol. V., 1893, PP- 1—83 (2 pi.). 



