710 Sargant.—-Recent Work on the Results 
Miss Thomas’ suggestion is that in cases of cross-fertiliza¬ 
tion the endosperm formed as the result of a nuclear fusion 
which includes a male element—the twin-structure of the male 
element in the fertilized ovum—may be more suitable for the 
nourishment and development of the embryo arising from 
the same mixed stock than an endosperm formed from the 
mother plant alone. The food-material, for example, contained 
in the cells of the crossed endosperm might agree better with 
the crossed embryo than that supplied by an endosperm 
of purely maternal origin. This appears the more probable 
as we know that one of the characters in which de Vries and 
Correns traced the influence of the pollinating Maize-plant 
was the presence of sugar within the endosperm-cells in place 
of starch. 
But if the endosperm is more fitted for its work by the 
presence of mixed characters, we must consider the phenomena 
of amphimixis as essential to the process of nuclear fusion 
which gives rise to the endosperm. In this case we can hardly 
refuse to regard it as now a true act of fertilization, however 
it may have arisen. 
It appears to me possible that this view of the increased 
utility of the endosperm of mixed origin may partly account 
for the surprising effect of cross-fertilization in the first 
generation of plants remarked on by Darwin. He speaks of 
the good effects of cross-breeding as appearing much sooner 
in a race of plants than in one of animals. If the food supplied 
to the embryo is rendered more nourishing at the same time 
that the embryo itself gains in vigour, the effect of a cross 
would be doubled in a single generation. 
Literature. 
I. Papers on Double Fertilization since 1899 :— 
1. Correns: Untersuchungen iiber die Xenien von Zea Mays. : Ber. d. deut. 
bot. Gesell., 1899, P- 4 IC - 
2. --• Referat der Bot. Ztg., 1900, p. 240. 
3 . Guignard, L.: Sur les antherozo'ides et la double copulation sexuelle chez 
les vegetaux angiospermes: Comptes rendus, Acad. d. Sci., Paris, 
April 4, 1899. 
