40 



ELEMENTS OF BOTANY. 



Every farmer knows that if two varieties of corn, say yellow and white, 

 be planted side by side, the result will be a great many ears of speckled 

 corn, those with both white and yellow kernels intermingled. Now, corn 

 is a monoecious plant, the pollen being produced in vast quantities by the 

 tassels (stamens), while the silk of the ears represent the exposed portions 

 of the pistils. Naturally two varieties growing side by side will have their 

 showers of pollen intermingled by the wind, and grains of each falling 

 upon the silk of the same ear will produce a mixture of different colored 

 kernels, for the pollen will determine the character of the kernel produced 

 by the ovule which it fertilizes. 



Again, the pumpkin and squash are closely related species, and cannot 

 be grown side by side without hybridization. But, as in the animal king- 

 dom, the production of hybrids is limited to closely related species or 

 varieties, and cannot be effected by the crossing of in- 

 ^f\ dividuals of widely different genera. Strictly speaking, 



the hybrid is the product of the crossing of related 

 species, but in a wider sense it may, without impro- 

 priety, be applied in plant life to the crossing of varie- 

 ties, as in the instance of corn. 



THE FRUIT. 



The fruit is the fertilized and matured ovary en- 

 closing the seeds, capable of reproducing the plant. 

 Not unfrequently, also, it comprises the remaining 

 parts of the pistil, more or less altered, or the enlarged 

 and variously modified calyx and receptacle. 



Fruits are distinguished as simple or compound. 

 A simple fruit consists of a single matured pistil, 

 whether this be simple or compound, together with its 

 enclosed seed or seeds, the seed-vessel, termed peri- 

 carp, being the matured ovary, and the seed the ferti- 

 lized and matured ovule. 



The pericarp is distinguished into three layers, 

 namely, epicarp (outer layer), endocarp (inner 

 layer), and mesocarp (middle layer). In many fruits 

 the mesocarp is very thick and fleshy, and is then 

 known as the sarcocarp. 

 There are three principal kinds of simple fruits, fleshy fruits? stone- 

 fruits, and dry fruits- 



In fleshy fruits the whole pericarp thickens and becomes soft in ripen- 

 ing. Of this kind are the berry, pepo, and pome. 



In the berry the flesh is uniformly soft throughout, as in the cur- 



Fig. 79.— Currants- 

 berries. 



