254 PRACTICAL COURSE IN BOTANY 
for instance, in producing tubers or in growing bulbs, — 
itis apt to bear few seeds and to depend more or less com- 
pletely upon other methods of reproduction. 
Among cultivated plants, selection on the part of man, 
whether conscious or unconscious, has perhaps contributed 
more than any other cause to bring about the same result. 
To this agency is probably due the development of our com- 
mon domestic fig, of which over four hundred varieties that. 
mature fruits without fertilization are cultivated in the United 
States alone. The fig was one of the earliest fruits known to 
cultivation; and the early navigators, ignorant of the processes 
of fertilization, would naturally, in choosing specimens to 
carry home with them, select only fruit-bearing trees. Such 
of these as matured fruits would be preserved and propagated, 
until, by repeated selection, hundreds of edible varieties have 
been developed that ripen fruits without caprification (279). 
287. The use of the fruit to the plant. — The object of 
the fruit is to furnish protection to the seeds during their 
period of development and inactivity, and to aid in various 
ways the work of dispersal. It probably takes part also in 
digesting and diffusing nourishment for the use of the develop- 
ing seeds. It has been shown in previous chapters that plants, 
almost without exception, are in the habit of storing up 
food in various ways as a provision for fruiting. That a 
large portion of the stored nourishment is used up in the per- 
formance of this function is proved by its disappearance from 
those parts — for example, from fleshy roots, such as beets 
and turnips, after they have “ gone to seed.” 
Practical Questions 
1. What is the use of the down on the peach? The bloom of the plum 
and grape? [202, (1); Exp. 91.] 
2. Why are apples, pears, plums, and other fleshy fruits nearly always 
rosier on one side than on the other? (Exp. 90.) 
3. Can annuals be improved in any other way than by seed selec- 
tion? 
4. Would a seedless annual be perpetuated under natural conditions? 
