9 o THE MECHANISM OF LIFE 



figures which characterize the phenomenon of karyokinesis. 

 This experiment consists not merely in the production of a 

 certain figure, such as is obtained in the magnetic spectre, but 

 in the reproduction of the movement itself, and of all the 

 successive forms which are seen in the natural phenomenon. 

 These are evolved before the eyes of the spectator in their 

 regular order and sequence. 



I may here reproduce the text of my communication at 

 Grenoble : " Until I introduced the conception of a field of 

 diffusion, there was no proper means of studying the 

 phenomena of diffusion, which obey the laws of a field of 

 force as expounded by Faraday. Moreover, no one suspected 

 the possibility of reproducing by liquid diffusion a spectre 

 analogous to the electro-magnetic phantom. Guided by this 

 theory of a diffusion field of force, I have been able to 

 reproduce experimentally the figures of karyokinesis by simple 

 diffusion. With regard to the achromatin spindle, Professor 

 Hartog has shown that the two poles of the spindle are of the 

 same sign, and not of opposite signs as was at first supposed. 

 In the process of karyokinesis the two centrosomes, i.e. the 

 two poles of the achromatin spindle, repel one another. They 

 must therefore be poles of the same sign. An electric or 

 magnetic spectre showing a spindle between two poles of the 

 same sign is unknown ; such a thing would appear to be an 

 absolute impossibility. What is impossible in electricity and 

 magnetism, however, is quite possible in the artificial diffusion 

 field ; we can here have a spindle between two poles which 

 repel one another — that is, between poles of the same sign. 

 Fig. iJl is a photograph of such a spindle produced by 

 diffusion. On either side are two poles of concentration, 

 which represent the centrosomes. each pole being surrounded 

 by a star-like radiation. These poles being alike, repel one 

 another. In the preparation one may see the distance between 

 the two poles slowly increase, the poles gradually separating 

 from one another just as do the centrosomes of an ovum 

 during karyokinesis. This preparation, then, which is pro- 

 duced entirely by diffusion, presents a perfect resemblance to 

 the achromatin spindle in karinevoksis. 



