84: PLANT LIFE OK THE FARM. 



wheat, .within the butterfly-shaped and brightly-colored 

 petals of the pea or the clovers, and the yellow petals of 

 the flowers of the turnip or the colza, the rape or the 

 mustard, are a series of fine thread-like bodies, the 

 " stamens," varying in number, size, and arrangement in 

 different flowers, but each consisting of a fine thread or 

 stalk, called the " filament." Surmounting this is a sort 

 of pocket or case, called the "anther," containing a yel- 

 low or greenish dust, which, when examined with a lens, 

 is seen to be made up of separate cells or grains, called 

 the pollen grains. Some idea of the number of these 

 pollen grains may be gained from the calculations of Mr. 

 A. S. Wilson, who estimates, from the actual counting 

 of a portion, that each anther of rye contains twenty 

 thousand pollen cells, five hundred thousand of which 

 are needed to make up one grain in weight. A floret of 

 spring wheat in like manner was found to contain six 

 thousand eight hundred and sixty-four grains, but, as 

 the pollen grains of the wheat are larger than those of 

 the rye, only three hundred and ninety thousand are 

 required to make up a grain weight. An acre of wheat 

 may, it is further calculated, produce fifty pounds of 

 pollen, and an acre of rye two hundred and twenty-four 

 pounds. 



Within the stamens, in most flowers with which farm- 

 ers have to do, is a " pistil," consisting of a thick portion 

 below, which contains the young "ovule" destined to 

 become the seed, and which is usually overtopped by a 

 little thread, called the "style," whose upper end, again, 

 is dilated into a " stigma." In the case of the wheat and 

 other grasses these stigmas are covered with fine white, 

 silky hairs. The essential constituents of the flower, 

 without which reproduction cannot be effected, are the 

 pollen grains and the ovule. All other parts of the 

 flower are mere accessories, and some of them are very 



