is shaded, and, consequently, a less number of stalks can be

raised per acre.

In some localities the ear may be too high on the stalk to be husked easily. While there are wide variations due to variety', soil, climate and thickness of planting, the weight of field-cured

stover has been esti mated at about one and one-third pounds for each pound of grain produced. In actual dry matter the yield per acre may be estimated as about equal under ordinary field culture. It has been estimated that for every pound of dry matter produce in the roots and stub ble when cut close to the ground, six pounds are produced in the plant above ground.1

214. The Inflores.

collectively the tassel. The carpellate flowers are borne in the

1 Wis. Rpt. 1892, p. 119. In this connection, see also Mo. Bul. 9.

axils of the leaves, forming upon maturity what is known as the ear. The fruit of the maize plant being borne in the axils of the leaves rather than being terminal is a feature which distinguishes maize from all the other cereals. The difference is more apparent than real. Certain varieties of maize, especially pod maize, sometimes bear carpels upon the tassel of the main culm, and where branches oc

cur bear both stamens and carpels at their end. It is assumed that wild naize was a branched plant containing perfect lowers (both carpels and tamens) on the terminal assel and, also, at the nd of the branches. Bince the plant is wind fertilized and the pollen ends to fall, the carpellate flowers in the terninal tassel would be less perfectly pollenized than those on the branches below. The pollen on the branches would tend to fall to the ground, thus being of little value. The plants which had the greatest development of carpels on the branches and of stamens in the terminal tassel would tend to survive. laden with a collection of grains (ear) the short branch would

Flint maize, variety Smut Nose. Compare with dent variety upon opposite page. Note two good ears with rudimentary one below upon main culm, and also the leaf blades upon the husks of the ear. The other three culms are suckers, all having grown from one seed. Plant has been in tassel about three weeks. (One-twenty-fourth natural size.)

As the end of a branch became

best hold the ear from drooping. Thus the culm of the branch (now called the shank) has become a succession of nodes with short internodes. Each node still bears the sheath of the leaf, the blade being much reduced in size or aborted. This collection of leaf sheaths is called the husk. The branch has been

telescoped. (211.)

215. The Tassel. The tassel is a spreading panicle generally a foot or more in length in field varieties, with branches usually six to ten inches long. The spikelets extending from base to tip of each branch (rachis) are arranged in clusters of two to four, one usually pediceled, the others sessile, or all sessile, the clusters often overlapping. The empty or outer glumes, about equal, three-eighths to one-half inch long, are stouter and harder than the flowering glume and palea. The latter are about equal and shorter than the outer glumes. They are hyaline and much thinner. Each flower bears three stamens. The anthers are large, nearly as long as the flowering glume. They are attached to the filament on one side near the lower end.

Lazenby estimates that 45,000 pollen grains are produced for each ovule in dent maize.1 According to another estimate, an average maize plant has seventy-two hundred stamens, contain. ing about eighteen million pollen grains. Assuming two thousand ovules to a plant, there would be nine thousand pollen grains to an ovule. It is held that the staminate flowers usually mature before the carpellate, but they may mature at the same time or later.

216. The Silk.-The style, commonly known as the silk, arises at the summit of the carpel. In certain varieties, as pop maize, the scar may be plainly seen on the top of the ripened grain. Since the end of all silks, for the silk to be effective, must protrude beyond the surrounding husk, the silk may be a 1 Proc. Soc. Prom. Agr. Sc. (1898).

2 Sargent: Corn Plants, p. 44.

foot or more in length. Near the base of the silk on the side opposite the embryo there is an opening through the wall of the ovulary to which has been given the name stylar canal. It is not known positively whether the pollen tube passes down through the substance 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.1 12 Whether the pollen tube before entering the stylar

tion; s, style or silk; c, the stylar canal through which, perhaps, the pollen tube enters the ovulary; i, inner glume; o, outer glume. Enlarged twelve times (after Poindexter).

canal grows down the outside of the A spikelet of maize before fertilizasilk 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 of from four to twelve inches in length and from eight to twenty-four rows 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 Spikelet and Grain of Corn Ohio Naturalist, Vol. IV, No. 1, Nov. 1903.

of the rachi forms the cob. It is interesting to observe that the development of the cob seems to be in some measure de

Thirty rows.

Eight rows.

pendent upon the development of the grains. As the tip of the cob develops last, ears are likely to be more tapering where soil or seasonal conditions have been unfavorable. A tapering ear may, therefore, in some instances, indicate a lack of

adaptation to the locality in which it is grown.1

In the cultivated varieties the glumes and paleae are reduced to small membranous parts around the base of the grains. In the pod maize, however, the glumes are very large, completely enclosing the grains.

The several rachi which make up the cob usually grow nearly straight from butt to tip; hence the two-ranked spikelets result in grains being usually arranged in regular order. These pairs of ovularies are fertilized with such certainty that under normal conditions an odd number of rows never results. Even where the number of rows is less at the tip end than at the butt, the number of rows remains even,-the reduction in number is made by the omission of a piece of the rachis. The case of an ear having twenty-one rows has been reported, but if authentic, is certainly a very rare instance.

218. The Position of the Ear.-The position of the ear on the culm (stalk) varies more widely than does the ratio of grain to stover. In some varieties the ears may be too high or too low to be easily husked. When too high, the stalks are more easily blown down. Four feet above ground is a desirable height for ears of medium sized varieties. The shank by which

1 Torrey Bul. 21, No. 12 (1894), p. 514.

Trans. Mass. Soc. Prom. Agr. 1858, p. 114