584 
C. F. U. MEEK. 
a denial of the existence of all chromosomeless spindles, 
affirming that their appearance is an illusion. Baltzer, how- 
ever, produced figures that cannot be thus explained, and 
said that the same conclusion must be drawn in the case of 
other spindles independently shown by Wilson ; moreover, he 
pointed out that in the animal cell every spindle is at first 
chromosomeless. Grallai’do now admits the existence of such 
spindles, and says, “Une difficulte se presente pour expliquer 
le petit fuseau primaire pendant I’eloignement des centro- 
somes; mais on pent admettre avec Eoriques (1911) que ce 
fuseau est forme par I’etirement du milieu visqueux du 
cytoplasma. Cette meme viscosite et elasticite du milieu 
cytoplasmique peuvent expliquer les rares cas connus de 
fuseaux sans chromosomes.” Let us consider this explana- 
tion. Now, if the form of the spindle is controlled, as he 
affirms, by forces other than the electric charges at the poles, 
all the forces concerned either can or cannot be represented 
by resultants at these points. We will suppose that they can 
be so represented. In this case a spindle cannot be formed 
between like poles, nor can an anti-spindle be converted into 
a spindle without at the same time changing the signs of the 
poles from like to unlike. But, if the signs are thus changed, 
the theory of spindle formation is at once disproved by 
Baltzer’s triaster in which two spindles carrying chromosomes 
are united to one that is chi'omosomeless ; moreover, if the 
poles of the primary spindle are unlike, other forces must be 
invoked to explain their divergence, because unlike charges 
cannot cause repulsion. We are therefore compelled to 
assume the alternative, viz. that the action of the various 
forces concerned in spindle formation cannot be represented 
by resultants at the poles : and, if this is so, the spindle can 
no longer be regarded as a figure formed entirely by forces 
acting at the centrosomes ; consequently the conclusion at 
which we arrived in our criticism of Hartog’s theory appears 
to be justified. 
We must now ask how far this conclusion affects Giallardo’s 
interpretation of cell division ; for the conformation of the 
