DISPOSITION OF CHROMOSOMES IN MITOSIS. 2O3 



attempted to determine what the possible and stable configura- 

 tions that is, the conditions of equilibrium are for any given 

 number of chromosomes up to twelve. 



Figures 3, 4 and 5 give exact representations of configura- 

 tions shown respectively by groups of four, eight and twelve 

 simple loop-shaped chromosome models. It should be added 

 that the number of possible configurations becomes very great 

 when the number of chromosomes is large. In the full paper 

 drawings of a number of these will be given. I shall then con- 

 sider the condition of their formation in greater detail. 



It is my intention to investigate further the possibilities of this 

 type of magnetic model. It is possible that such phenomena as 

 the aggregation of the chromosomes in a single plane, their longi- 

 tudinal splitting, and the separation of the daughter-chromo- 

 somes, may be simulated by means of such models. Much light 

 may thus be thrown upon the mechanics of these characteristic 

 phenomena. 



It is to be noted that in experiments of the above type the 

 filaments and chromosomes are arbitrarily confined in their move- 

 ments to a single plane, that 01 the surface of the water. In this 

 respect such models are incomplete, since, in the cell, movement 

 is possible in all three dimensions. It seems clear, however, 

 that, setting aside this partial and incidental limitation, these imi- 

 tations of cell-phenomena are often surprisingly true to nature. 

 /// so far as regards the mode of disposition of the chromatic fila- 

 ments and of the rows of magnets, the observed resemblance 

 may be held to imply an identity in the essential determining 

 conditions. These conditions are those of mutual attractions 

 and repulsions, which are common to both systems. In other 

 respects, it need scarcely be said, the two systems are widely dif- 

 ferent. Still, so long as science proceeds, as it has always done, 

 by the progressive identification of apparently widely different 

 things it will be necessary to isolate by analysis the features in 

 which otherwise diverse phenomena agree, and to disregard, for 

 the time being, their differences. We may with justification 

 infer from the above that attractions and repulsions- -here un- 

 doubtedly electrostatic in nature, since colloid bodies are con- 

 cerned - - play a most important part in determining the disposi- 



