582 
C. F. U. MEEK. 
the arguments from which he has concluded that the spindle 
is formed by a new force. We find at once that the conclu- 
sion rests upon a belief that the spindle is formed by a force 
acting only at its poles, and, since the reasoning is logically 
valid and the other premises appear to be irrefutable, we 
must either accept the conclusion or reject the interpretation 
of spindle formation. Now we have already found that the 
action of a new force between unlike poles is inconceivable in 
certain figures ; we must therefore choose between a method 
of spindle formation different from that assumed and the 
acceptance of a new force acting between like poles. But we 
have also found that the latter involves the further assump- 
tion that in the universe two sets of physical principles exist, 
diametrically opposed to one another. Consequently the new 
force must be I’egarded as a special creation in the narrowest 
sense of the words. We know that special creation has been 
the refuge of the baffled investigator throughout the 
history of scientific thought, and that it has seldom or 
never proved itself to have been justified : and in the circum- 
stances I prefer to think that the spindle is not formed by a 
force acting only at its poles, rather than that it is the visible 
expression of a force whose action violates the principles upon 
which physical science is at present based. 
Let us now turn to Grallardo’s interpretation. This assumes 
that the centrosomes and chromosomes in mitosis carry 
respectively positive and negative electric charges; that the 
spindle, as seen in the metaphase, is composed of two spindles, 
each formed between a centrosome and the chromatin of the 
equatorial plate; and that cell division is a bipolar pheno- 
menon, primarily electro-colloidal in nature. Let us consider 
first the assumption that the chromosomes carry negative 
electric charges. This was suggested by certain experiments 
of Lillie, who found that free nuclei and spermatozoids move 
towards the anode when placed in an electric field ; moreover, 
Pentimalli, corroborated by McClendon, has since shown that 
the chromosomes move towards this pole when an electric 
current is passed through the cell. We know that particles 
