246 PLANT LIFE 
wheat) with “albumen” or endosperm. It 
is a very remarkable fact, this second fusion. 
The sperm nucleus which takes part in it is 
the sister nucleus of that sperm which fuses 
with the egg. Hence it might be expected 
that it would carry paternal characters, and 
that these might make themselves felt in 
the nature of the endosperm to which the 
triplicate nucleus gives rise. It turns out 
that the expectation is realised, and where 
the endosperms of the pollen parent and the 
seed parent differ in a well-defined character, 
e.g. in colour or sugar contents, the char- 
acter imported by the sperm from the pollen 
may dominate the whole endosperm. ‘Thus, 
when pollen grains of different varieties of 
Indian Corn are blown on to a female ear, 
the endosperm of some of the grains will be 
found to be affected by the characters borne 
by the strange pollen. And it is just these 
identical grains that will betray evidence of 
hybrid characters in the embryo which each 
of them contains. For the same pollen grain 
provided both the sperm for fertilising the 
egg, and also the second sperm which formed 
part of the triplicate combination from which 
the endosperm originates. 
When fertilisation has been accomplished, 
remarkable changes are produced, not only 
within the ovule, but outside it as well. 
Within, the endosperm arises, by the re- 
peated division of the triplicate nucleus as 
already explained, while at the upper end 
