Page:Proceedings of the Royal Society of London Vol 60.djvu/309

Rh grounds for inferring the existence of a telegonic influence. But it is clear that if there be anything of the nature either of a periodic or of a secular change in stature going on, then since men are taller than women, any group of younger women will appear closer to their fathers than to their mothers, when com pared with a group of elder sisters. Thus, no legitimate argument as to a telegonic influence can be based on such a result. I have purposely considered this method of approaching the problem, because it is the method which first occurred to me, as it probably may do to others. It can very easily, however, lead to our mistaking for a real telegonic influence an effect of periodic or secular evolution, or, indeed, of different conditions of nurture.

(7) In conclusion, we may, I think, sum up th e statistics discussed in this paper as follow s:—

(i) So far as stature is concerned there is no evidence w hatever of a steady telegonic influence of th e m ale upon the female among mankind.

(ii) I t is improbable th at the coefficients of correlation which measure the strength of heredity betw een parents and offspring are constant for all classes even of the same race. For stature in the case of parents and offspring of both sexes, the value 0‘42, or say 3/7, may be taken as a fair w orking value, until more comprehensive m easurem ents are made. This makes hereditary influence in the direct line stronger th an has hitherto been supposed.

(iii) The divergence between the results of this memoir and that of the form er memoir on “ Regression, Heredity, and Panmixia ” would be fairly well accounted for, if there be a hitherto unobserved correlation between the hereditary influence and the fertility of woman.

The remarkable magnetic properties of liquid oxygen were pointed out by one of us in a communication to the Royal Society in 1891,