. The cereals in America. STRUCTURE OF MAIZE 147. foot or more in length. Near the base of the silk on the side opposite the embryo there is an opening through the ^vall oi the ovular}' to ^vhich has been given the name st^'lar canal. It is not known positively whether the pollen tube passes down through the sub- stance of the silk, entering the ovulary by way of the base of the silk, or whether the pollen tube enters the ovulary through the stylar canal. Guignard and others believe the latter to be the case.^^ Whether the pollen tube before entering the stylar canal grows dow^n the outside of
. The cereals in America. STRUCTURE OF MAIZE 147. foot or more in length. Near the base of the silk on the side opposite the embryo there is an opening through the ^vall oi the ovular}' to ^vhich has been given the name st^'lar canal. It is not known positively whether the pollen tube passes down through the sub- stance of the silk, entering the ovulary by way of the base of the silk, or whether the pollen tube enters the ovulary through the stylar canal. Guignard and others believe the latter to be the case.^^ Whether the pollen tube before entering the stylar canal grows dow^n the outside of the silk or whether the pollen grain by some mechanical means reaches the opening to the stylar canal is likewise unknown. After pollination, the silk dries up but persists. When, however, pollination is prevented, the silk grows to unusual size and remains green two or three times as long as normal. 217. The Ear.—The ear may vary from one-half an inch to sixteen inches long and may have from four to forty-eight rows in individual ears. A variation o[ from four to twelve inches in length and from eight to t^vent}^-four row^s is not uncommon and may obtain as a variety characteristic. The ear may be looked upon as being formed by the growing together of four or more spikes, each joint of the rachis bearing two spikelets. Each spikelet is two-flowered, the lower one being abortive (214); thus the distinctly paired rows often observed represent a pair of spikelets. The growing together 1 Guignard, L.: La double fecondation dans le mais. Jour. d. Bot 15 : 1-14. No. 2, 1901. 2 Poindexter, C. C: The Development of the SjMkelet and Grain of Com Ohio Naturalist, VoL IV, No. i, Nov. 1903. A spikelet of maize before fertiliza- tion ; s, style or silk ; c, the stylar canal through which, perhaps, the pollen tube enters the ovulary; i, inner glume; c, outer glume. Enlarged twelve times (after Poindexter).. Please note that these images are extracted from scanned page images that may hav
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Keywords: ., bookauthorhuntthom, bookcentury1900, bookdecade1900, bookyear1904
