THE PLANT AS A WORKING MACHINE 15 



the corolla are the stamens ; and at the center of the flower 

 is the pistil. Within the enlarged stamen tip, or anther, are 

 many grains of pollen, and within the swollen basal part of 

 the pistil (the ovary) are one or more ovules. Tb^ nvnlp^ 

 are the developing seeds. 



In such plants as indian corn and other members of the 

 grass family, to which corn belongs, staminate (stamen-bear- 

 ing) flowers are often found on one part of the plant and 



FIG. 10. A young ear of sweet corn 



A, entire ear, showing the joints, or nodes (n), and the internodes (i) of the branch 

 which bears the ear; the leaf-like bracts (6) which inclose the ear, and the grain, 

 or ovary (o), to each of which one of the silks is attached. B, an enlarged dia- 

 gram of one grain, showing the embryo sac (e), the inclosing husk, or chaff (h), 



and the silk (s) 



pistillate (pistil-bearing) flowers on another part (figs. 10 and 

 11). In corn the staminate flowers are known collectively as 

 the tassel, and the pistillate flowers collectively as the ear. 

 Each staminate flower consists of a simple leaf-like bract 

 which incloses three stamens. The amount of pollen borne 

 by a single tassel is very great; it is estimated by one au- 

 thority 1 that from 20,000,000 to 50,000,000 pollen grains 

 have been borne by a single corn plant. A single pistillate 

 flower consists of a short and obscure bract (often called 



1 DeVries, Plant Breeding. The Open Court Publishing Company, 1907. 



