Students' handbook to accompany Plants and their uses . ng) flowerson another part (figs. 10 and11). In corn the staminate flowers are known collectively asthe tassel, and the pistillate flowers collectively as the staminate flower consists of a simple leaf-like bractwhich incloses three stamens. The amount of pollen borneby a single tassel is very great; it is estimated by one au-thority1 that from 20,000,000 to 50,000,000 pollen grainshave been borne by a single corn plant. A single pistillateflower consists of a short and obscure bract (often called 1 DeVries, Plant Breeding. The O
Students' handbook to accompany Plants and their uses . ng) flowerson another part (figs. 10 and11). In corn the staminate flowers are known collectively asthe tassel, and the pistillate flowers collectively as the staminate flower consists of a simple leaf-like bractwhich incloses three stamens. The amount of pollen borneby a single tassel is very great; it is estimated by one au-thority1 that from 20,000,000 to 50,000,000 pollen grainshave been borne by a single corn plant. A single pistillateflower consists of a short and obscure bract (often called 1 DeVries, Plant Breeding. The Open Court Publishing Company, 1907. 16 INTRODUCTION To IJOTANY >-/i,nr) and an ovule with an elongated *////,- (called silk incorn), which gro\\s atlaclicd to the ovules tip. The tip oftht- style, •>!• silk, is the xt!</,,i<i, which is the roughened,stirkv surface to \\hieh pollen grains may adhere when theyfall upon it. 13. The seed. From a pollen grain which has fallen on thestigma there grows down\\ard through the style a very small. I to. 11. T\vi) linmrhrs 1ripiii the tassel staininate flowers t ulie ( the ])ollen tnlie ), which finally reaches the interior of theoMilc, where there is a very small e^. This egg is fertilizedliy its union with a small, v carried hy the pollen tube,and from the result of this fert ili/at ion a new emUryo cornplant develops within the ovule. While still within the de-veloping ovule, or seed, this young plant produces its roottip and stem tip: in corn and other grass seeds there is aspecial structure ( scutellum ) hy means of which the embryo THE PLANT AS A WOEKING MACHINE 17 plant absorbs food material from the ovule. While the em-bryo plant is developing, food material is constantly beingtransported into the grain, or ovule, until finally a relativelylarge amount of food material is thus deposited (fig. 12).The ripened seed, or grain, consists of the old ovule wall,the stored food material, and the embryo corn plant. The
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