240 
THE FRUIT 
Blackberries and raspberries are collections of small drupes 
which make up an aggregate or collective fruit. In the case of 
raspberries, the fruit separates from the receptacle which re¬ 
mains on the stem. In blackberries it does not separate, but 
the receptacle is removed from the stem as part of the fruit. 
Accessory fruits are fleshy fruits in which the pericarp 
may be seated upon the receptacle or it may be inclosed by 
it. The strawberry has 
a fleshy receptacle in 
which the true fruits, 
akenes, lie in depressions. 
Multiple fruits are 
those in which two or 
more separate flowers 
may blend into a single 
mass, as in the mul¬ 
berry and the pineapple. 
Pineapples, through long 
cultivation, have lost the 
habit of producing seeds. 
213. Seed Dispersal. 
— Before any fruit has 
fulfilled its function, it 
must scatter the seeds it 
contains. This is neces¬ 
sary for three reasons, at 
least. (1) There would 
be too much competition 
if all were dropped near 
together; (2) there would 
be too slow progress, for 
the soil near the parent 
might be depleted, and the new plants could not grow as well 
there as in fresher soil; and (3) there would be too great a 
chance of extermination if all were dropped near together, for 
Figure 230. — Seed Dispersal of Milk¬ 
weed. 
The pod opens, exposing the seeds. The 
air causes the long, silky hairs attached 
to each seed to dry and spread, helping to 
force the seeds from the pod, and enabling 
the wind to carry them long distances. 
