THE AMERICAN BOTANIST. 73 
certain "polar nuclei" and other bodies. When fecundation takes 
place, one of the two nuclei of the pollen-tube passes out of the 
tube into the embryo-sac, and there comes in contact with, and 
fuses with, the nucleus of the egg-cell, which thus develops into 
the embr>'o plant. 
But, as we have seen, there are two nuclei in the pollen-tube ; 
one is accounted for as just mentioned. What becomes of the 
other ? The answer to this question has been supplied by Nawas- 
chin in Russia, by Guignard in France, and by Aliss Ethel Sargent 
in our own country. From their researches it appears that, as has 
already been recorded in these columns, there is a double process 
of fertilization. Both the pollen-nuclei enter the embryo-sac, one 
to fuse with the nucleus of the egg-cell, and the other with two 
"polar nuclei" which form the nucleus of the embr}'o-sac. From 
this last nucleus, by repeated sub-division, the ''endosperm," which 
surrounds the embr\'o and supplies it with food, is developed. 
According to this, then, not only is the embryo-plant the result of 
the confluence and fusion of nuclei derived from the male and the 
female respectively, but the endosperm or the albumen of the seed 
has a like double origin. Now, it is supposed by De Vries and 
others, that the occurrence of "Xenia," or the direct influence of 
the pollen on the female plant, may be explained as 
result of the influence of one of the pollen-nuclei 
on the endosperm-nucleus. A\'e do not understand 
how the walls of the ovary (the pericarp) and the coats ot 
the seed can be aft'ected by anything that takes place in the endo- 
sperm. ]\Ir. A\'ebber is endeavoring to clear up the matter by ex- 
periments with maize, w^hich is peculiarly liable to manifest ap- 
pearances attributable to the influence of the pollen, and therefore 
obsen-able, not only in the new seeding plant, but also in the par- 
ent mother plant. We often come across parti-colored grains in 
a head or cob of maize, and the late Mr. Laxton show^ed us many 
such cases in the seed-coats of maize. Mr. Webber's experiments, 
so far as they go, support the conjectures of De V ries, and the ex- 
periments of Heari Vilmorin. It is needless to do more than al- 
