Common varieties of corn in the Guatemalan highlands. A little less than natural size (note centimeter scale at the base).
Left: Typical ear of white corn from the region around Antigua. Note the slightly enlarged and differentiated base, the gently tapering ear, the flinty kernel with a conspicuous cap of soft starch.
Right: Typical ear of yellow corn from the highlands. This one was grown at Quezeltenango from seed obtained at Salcaja. The wide flinty kernels were deep yellow; some of them had a slight capping of soft starch. The enlarged base and the slightly irregular kernels are typical. One of the ears from Nos. 1 and 2 of the Appendix.
Ears to the same scale as pl. 47
Left: Ear of white corn from Quezaltenango. In its high row number and pointed kernels this variety resembles the common corn of central Mexico. So No. 25 in the Appendix.
Insert: Kernels of popcorn from Patzun, slightly larger than natural size (note millimeter scale along the top edge of the plate).
Right: Ear of yellow corn from Zunil (see No. 23 in the Appendix). This is basically an 8-rowed variety with varying amounts of "multiplication." The ear illustrated here has so many extra kernels (due to "multiplication" in the sense used by Cutler, 1946) that the base 8-rowed condition is almost impossible to follow.


The Appendix, in so far as space permits, gives a full presentation of the facts summarized in Table 1, along with other relevant data on variation. For many of the collections a Leica snapshot of a random sample of a few ears shows their general over-all appearance. These pictures are printed at approximately the same magnification. The sliding micrometer used in measuring the cars appears in each picture and can be used to make exact comparisons since it is set at 5 cm.

The population diagrams are of practically the same type as those used in "Maize in Mexico" Anderson, 1946). While they look like correlation tables they are a much simpler device and are more like a scatter diagram; they are merely a way of showing graphically the kernel width, row number, denting of the kernel and pointing of the kernel of each of the cars in the standard 25-ear sample. Since each of the characters is a multiple factor character, and since each is at least partially independent of the other three genetically, the combination of all four provides a record of a good portion of the germ-plasm. The diagrams can be used as a record of what was growing at a particular place and time, as a means of making exact comparisons between varieties or between different fields of the same variety, or (analytically) to examine the effect of a certain variety on the morphology of others being grown in the same neighborhood.

Each little glyph (circular or pointed as the case may be) represents one ear of corn. Its shape denotes the shape of the average kernel on that ear (pointed. slightly pointed, without in obvious point); its color represents the texture of an average kernel. Texture was scored as follows: open circle, no soft Starch at the tip of the kernel; open circle with a dot, cap of soft starch but no indentation of the kernel; upper quarter of the circle filled in, cap of soft starch leading to a small indentation of the kernel; upper half of circle blackened, so much soft starch that there is a deep indentation in the kernel but no fine wrinkles on its surface; upper three quarters of the circle blackened, a denting of the kernel plus fine wrinkles in the seed coat; entire black circle, soft starch deposition so extreme that there is a deep wrinkled dent in the tip of the kernel and it is more or less collapsed (this condition, though common in central Mexico, was rare in the part of Guatemala covered by these studies). In other words, the blacker the glyph, the greater is the amount of soft starch.

The diagram can be thought of ms a set of pigeon-holes simultaneously cataloguing the ears with regard to their row number (upright scale) and their kernel width (horizontal scale). It sorts out the ears into a series of squares, and all the dots falling in each square represent ears having the same row number and kernel width. The glyphs are arranged in a standardized fashion around the center of each square; variations in position within each of these squares are of no significance. In one or two instances a bar at the side of the glyph is used to mark certain special ears (such as those reserved for seed, or nubbins, "mulcos", etc.).