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Page:Popular Science Monthly Volume 68.djvu/65

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WHAT IS AN EAR OF CORN?
61

rudimentary (Fig. 9). The lodicules are very prominent in the staminate flowers, and will usually be found more or less reduced in hermaphrodite flowers, but they entirely disappear in the pistillate flowers.

Fig. 12. Pistillate Flower of Dent Corn, very young, carpel not yet closed, r. Rudimentary lower flower magnified 65 diameters.

Fig. 14. Drawing from photograph of a Sweet Corn Plant to compare with Diagram Fig. 13. Note that the number of nodes in the shortened ear-bearing branches corresponds exactly to the number of nodes in the main stem above point of attachment.

The lower rudimentary flowers may be found in the pistillate flowers of all types of cultivated corn (Fig. 12). The abortive ovary is soon absorbed, but the palet and glume remain to form a part of the 'chaff' on the ordinary corn cob. Fig. 13. Diagram illustrating Probable Structure of Early Progenitor of Corn Plant. The development of the central spike into an ear may now be easily traced. First, the pedicellate spikelet in each pair of spikelets becomes sessile so that we have a pair of sessile spikelets as in Fig. 5, c. Then the upper flower in each spikelet becomes a perfect pistillate flower, while the lower flower in each spikelet becomes an abortive pistillate flower. The pairs of spikelets on the central spike are in four to eleven or more rows, so that by the mere development of the central spike of the tassel into