Let me try to sift out the facts. And first we must inquire on what grounds this opinion is based. I have already alluded to the general belief in the greater degree of variability in men, which, if established, would on the psychical side involve an accentuated individualism and hence a greater possibility of genius. This view has been supported by John Hunter, Burdach, Darwin, Havelock Ellis, and others. Ellis, in the chapter on "The Artistic Impulse" in _Man and Woman_, says, "The rarity of women artists of the first rank is largely due to the greater variational tendency of men." Now, this biological fact is certainly of great importance, _if it can be proved_. But can it? It has recently been contested by anthropologists at least as distinguished as those who have given it their support. Manouvrier, Karl Pearson, Frossetto, and especially Guiffrida-Ruggieri have brought forward evidence to prove the fallacy of this belief in the slighter variability and infantile character of woman. Now, it is clearly impossible for me in the space at my command to go into the conclusions brought forward on both sides of this difficult question. What I want to make clear is that this greater variability of man has not been established, and therefore cannot be accepted as a condition of male genius. I am glad to be able to give a statement on this question by Professor Arthur Thomson, which will sufficiently show that my opinion is not put forward wantonly and without due consideration, but that it coincides with the conclusion of one who is an acknowledged leader in the advanced biological study of the sexes. Professor Thomson writes thus[321]--