472 RHMMAKY 01' CURRKNT KKSKARCIIKS KKLATIXQ TO 



Hsematozoa in Cold-blooded Animals.*- Prof. B. Danilewsky 

 lias (liKcuvcred a new Ilituiatd/ooii, which }w calls Hcemngreyarma 

 (cistii(liiiix) Stcphnmncl. It is iiionocoUular and worm-like, and \H 

 " indisputably an intracellular parasite in the red blood-corpuscles of 

 Emits liitiirio." Uanilowsky compares the animal with tlic Cytozoa of 

 Laukester, and has no doubt that tlie latter's view as to Drepanidium, 

 etc., is correct. 



Artificial Division of Infusoria.! — Prof. M. NuE,sbaum has ob- 

 tained some interesting results as to tlie regeneration of unicellular 

 organisms. 



He divided an Oxytiicha into two halves either longitudinally or 

 transversely and found the edges at the point of division were soon 

 surrounded with new cilia. Notwithstanding that sometimes some of 

 the body-substance or even a nucleus was lost during the operation, 

 the two halves became normal animals with four nuclei and the 

 characteristic ciliary ai)paratus. The anterior portion formed a new 

 hinder-part, and the right half a new left. Tlie complete organisms 

 thus formed again developed by spontaneous division ; one 0.vi/tricha 

 after being cut in halves, pri educed ten normal individuals, all of 

 which afterwards became encysted. Even pieces of unequal size grew 

 again, but those without a nucleus appear to have no such vital power ; 

 BO that a nucleus seems to be essential to the retention of the regene- 

 rative power of a cell. Parts with nuclei may, however, not recover 

 if the healing of the injured portion does not take place quickly 

 enough. This was observed in experiments with multinucleated 

 Opalince, but not with multinucleated vegetable cells. 



These experiments, Herr Nussbaum considers, demonstrate that 

 it is possible to divide every cell artificially if the proper conditions 

 for the experiment are discovered. He also says, " That which Fol's 

 observations first taught us and which was insisted upon by Pfliiger 

 and Strasburger, viz. that the egg-cell is potentially a multiple of 

 individuals, is by these experiments still further extended. All the 

 energy developed by the cell is attached to a divisible substratum. 

 The power of division, the potential capacity for increase of the indi- 

 ■ vidual cells, is not only present during natural division or the processes 

 that precede it, but is present at all times." 



Simultaneously with Herr Nussbaum's exjjcriments. Dr. A. Gruber + 

 has artificially divided Stenior ccendeus. When divided transversely 

 through the centre the posterior section in twelve hours developed a 

 new peristomial area with the large cilia and oral spiral. The part con- 

 taining the mouth also added a new posterior portion. A longitudinal 

 division througli the peristome was followed by the same regenerative 

 process, two complete peristomes being again formed. Pieces smaller 

 than a half also again formed complete individuals, though it could 

 not be determined whether this occurred in the case of pieces not con- 

 taining any portion of a nucleus. That even a small remnant of 



* Arch. f. Mikr. Anat., xxiv. (1885) pp. 588-08. 



t SB. Niederiheinisch. Gesell. f. Natur- uiid Heilkuiidc. 1884, pp. 259-63. 

 I Biol. Ctnlralbl, iv. (1885) pp. 717-22. See Naturforscher, xviii. (1885) 

 pp. 93-4. 



