Karyokinesis 355 



whatever, which warrants the inference that it is repul- 

 sion which operates between the two halves. 260 



2. Hanseman's observation, that during karyo- 

 kinesis all the peculiarly vital functions of the cell, 

 as assimilation, secretion, etc., etc., are completely 

 suspended. 261 



3. Watase's observation, according to which the 

 centrosome in reality is only a simple cytomicrosome but 

 of greater circumference and greater force of attraction, 

 and that the cytomicrosomes which always lie at the meet- 

 ing point of three or more cytoplasmic fibers likewise are 

 nothing else than small temporary clumps quite aspecific 

 which form anew in each cell division from the contract- 

 ing substance of the cytoplasmic fibers themselves. 262 



4. Ziegler's experiment, in which the poles of the 

 horseshoe magnet took the place of centrosomes and acted 

 upon iron dust strewn upon a thin horizontal wax plate 

 upon which previously pieces of iron wire of forms 

 similar to that of the chromosomes had been placed, and 

 in which figures were obtained \vhich were similar to 

 those presented in nuclear division, which is a direct 

 proof of the conception already advanced by Roux, that 

 in the attraction exerted by the centrosomes upon the 

 chromosomes there are in play static energies of nature 

 similar to that of magnetic force or of static electricity. 263 



2a Delage: L'heredite etc. P. 149 150. 



z81 Hansemann : Studien iiber die Spezifizitat, den Altruismus 

 und die Anaplasie der Zellen. P. 10. 



262 Watase: On the nature of Cell-organisation. Biol. Lect. at 

 the Mar. Biol. Lab. of Wood's Holl, Summer Session, 1893. Bos- 

 ton, U. S. A., Ginn, 1894. P- 92 93 ; und Origin of the Centrosomes, 

 Ibid. Summer Session 1894; Ginn, 1896. P. 282, 285. 



283 Ziegler: Untersuchungen iiber die Zellteilung, Verhandl. der 

 Deutschen Zoolog. Gesellsch., Leipzig 1895. P. 78 83. Roux: 



