304 Saunders. 
and further that the general conclusions underlying this scheme can 
either be directly tested, or can be paralleled in the case of other 
characters in Stocks besides singleness and doubleness. 
Let us now see how GOLDSCHMIDT attempts to deal with these 
same facts. If I understand his view correctly, the only way in 
which he is able to deal with them is by ignoring those which are 
not compatible with his theory. It may be stated at once that the 
end which GoLDSCHMIDT has in view is, as he says in conclusion, to 
explain the method of sex inheritance in hermaphrodite plants. After 
giving his conclusions in regard to the sex constitution of herma- 
phrodite flowering plants in general, he proceeds to show in detail 
how in his opinion the facts regarding doubleness and plastid colour 
in Stocks are in agreement with his conclusions regarding sex, and 
can in fact be interpreted as a simple case of sex-limited inheritance, 
a view, which, as I hold, cannot be accepted. For a full exposition 
of his argument the reader must consult GOLDSCHMIDT’s own paper, 
but it will be convenient to give here a brief statement of his con- 
clusions before proceeding to discuss them. 
Goldschmidt’s Scheme. 
It is assumed in general 
(1) That hermaphrodite flowering plants are female in constitution 
and contain, if not an X chromosome an equivalent X substance in 
which the factor for femaleness (F) is located. 
(2) That taking only sex into consideration we may represent 
the chromosome constitution of the egg mother cells(1) as FFXX, that 
of each egg cell as FX. 
(3) That such hermaphrodite plants produce male gametes in 
consequence of the disappearance from the mother cells of one 
X chromosome, or of the F constituent of this X chromosome. 
(4) That the resulting pollen grains are therefore of two kinds, 
(a) those containing, and (b) those lacking XF. 
(5) That those lacking XF either degenerate or are incapable of 
fulfilling the function of fertilisation. 
And in particular 
(6) That singleness in Stocks is due to the presence of one factor 
— indicated by S. (Eversporting forms will therefore have the con- 
stitution Ss.) 
(1) The terms egg mother cell and pollen mother cell are here used in a general 
sense as the equivalent of GoLDSCHMIDT’S Ureier und Ursamenzellen. 
