140 REPRODUCTION IN PLANTS AND ANIMALS. 



branches and branchlets of the naked tree are not dead. 

 Life exists all along the central axis, and is lying in the 

 bud or hibernaculum of the young shoot, in a dormant 

 state, till spring awakens it to a new existence. Hence it 

 is, that every year, a plant with a ligneous persistent stem 

 increases in altitude, until it becomes a shrub or tree with 

 a noble canopy of foliage. Such may be fairly considered 

 as the highest developments of vegetable matter. 



The term fruit has a more extended signification in botany 

 than in ordinary language. It is applied to the full grown 

 ovary or pericarp, whatever may be its size, form, color, or 

 texture, and whether it is edible or not. A grain of wheat 

 or corn, or the pericarp of a sunflower or thistle, considered 

 botanically, is as truly a fruit as a peach, a gooseberry, or 

 a melon. 



Sometimes the texture of the fruit or pericarp remains 

 nearly the same as at first, or it may grow into a fleshy body, 

 which gradually changes into an agreeable pulp, as in the 

 grape. Occasionally the pericarp becomes crustaceous and 

 woody in its structure, as in the nut ; or it may become in 

 part hard and dry, like a nut, and in part a delicious pulp, 

 as in the plum and peach. 



There are few plants in which all the ovules become per- 

 fect seeds. Many are suppressed during their progress of 

 growth, so that frequently one seed is developed at the ex- 

 pense of several ovules. This is well seen in the prickly 

 pericarp of the chestnut, (Castanea vesca,) which, when 

 ripe, opens by four valves, and drops the one or two nuts 

 contained in its interior. In the ovary of the chestnut 

 there are usually fourteen ovules. Most of these how- 

 ever become abortive, or perish as the ovary ripens into 

 the pericarp ; whilst such as remain are generally very much 

 reduced in size, one or two nuts growing at the expense of 



