298 Saunders. 
the same way as in the case of certain animal hermaphrodites, he 
holds that this conception alone, without further assumptions, is 
sufficient to explain the results observed in the case of the double 
character and of plastid colour in Stocks. Consequently he regards 
as superfluous my suggestion that singleness results from the presence 
of two factors which in the pure-breeding (— non-double-throwing) 
singles are linked together, and are borne by all the gametes, but 
which in the eversporting (= double-throwing) singles have become 
free (unlinked), and are distributed among the female gametes, 
which alone carry them, according to a definite system of partial 
coupling. 
Both views, it may be noted, have been deduced from, and are 
intended to furnish an explanation of the same evidence, for GoLp- 
SCHMIDT states that his deductions are based upon the data I have 
given, and he does not himself adduce any additional observations. 
But the question at issue is not wholly one of interpretation. The 
crucial points of divergence in the two views relate to matters of fact. 
Having accumulated a certain amount of evidence I endeavoured to 
formulate a scheme which would fit the facts, and this the one I 
have put forward, so far as it goes, appears to me to do; nor do I 
gather that this is denied by GOLDSCHMIDT. GOLDSCHMIDT, on the 
other hand, proposes a scheme primarily intended to explain the sex 
constitution of hermaphrodite plants, and would then fain make the 
facts as to doubleness and plastid colour in Stocks fit this precon- 
ceived scheme regarding sex. What I hope to show clearly in the 
following pages is that the scheme of sex-limited inheritance which 
he suggests for the Stocks is not in agreement with the facts, and 
that his interpretation cannot therefore be accepted. 
The main facts which my scheme and GOLDSCHMIDT’s present 
suggestion are designed to explain are given in my paper in the 
Journal of Genetics(1!), and are summarised by GOLDSCHMIDT(?), and 
I therefore need not repeat them. But it will be convenient to have 
before us the conclusions which I have drawn from them, and I 
therefore quote below those which are material to this discussion. 
(1) Every individual in an eversporting strain yields doubles in 
excess; the proportion may be stated as 7+ x single to 9— x double 
where x is less than I. 
(1) loc. cit. See especially pp. 356—358. 
(2) loc. cit. 
