Karyokinesis 355 
whatever, which warrants the inference that it is repul- 
sion which operates between the two halves.2° 
2. Hanseman’s observation, that during karyo- 
kinesis all the peculiarly vital functions of the cell, 
as assimilation, secretion, etc., etc, are completely 
suspended.?6! 
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.?® 
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 which 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.?°* 
*6°Delage: L’hérédité etc. P. 149—I150. 
2611 ansemann: Studien iiber die Spezifizitat, den Altruismus 
und die Anaplasie der Zellen. P. 10. 
282Watasé: 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. 
2637iegler: Untersuchungen iiber die Zellteilung, Verhandl. der 
Deutschen Zoolog. Gesellsch., Leipzig 1895. P. 78-83. — Roux: 
