EFFECTS OF POLLINATION. 165 
fruits. The larger fruit (Fig. 56) has all the cells de- 
veloped and seed-bearing, while the smaller one (Fig. 57) 
has seeds upon one side 
only, and the other or un- 
fertilized side is seedless 
and-' nearly ‘solid. The 
original central division of ff 
this fruit is shown at A B. 
This experiment has been 
repeated several times with 
substantially the same re- 
sults. The flowers, of 
course, were emasculated 
in the bud, and were se- 
curely covered with bags 
. 56. Effects of liberal supply of 
to prevent any interference. pollen. 
Four important lessons are to be drawn from these 
experiments: 1. One-sidedness appears to be due to a 
greater development of seeds upon the large side.* 
2. This development of seeds is apparently due to the 
application of the greater part of the pollen to that side. 
3. An abundance of pollen applied 
over the entire stigmatic surface, by 
increasing the number of seeds in- 
creases the size of the fruit. 4. The 
pollen, either directly or indirectly, 
probably stimulates the growth of 
the fruit beyond the mere. influence 
A of the number of seeds; the growth 
eee ay scanty of the solid part in Fig. 57 appears 
supply of pollen. to indicate this. This secondary in- 
fluence of the pollen in increasing the size of fruits, both 
by means of increasing the number of seeds— which nec- 
essarily demand a larger envelope or receptacle —and 
* For similar results in the pollination of apples, see Bull. 31, Mich. 
Agr. Coll. g1 (1887). 
