540 
Journal of Agricultural Research voi. xxvn, no. s 
the degree of crinkly leaves, degree of lobing, and degree of color, each 
on a scale of from o to 9. Aside from these grades, the plants were classi¬ 
fied into normal and crinkly classes, with the result that 28.1 ±2.1 
per cent were adjudged to be crinklies. The fact that the second gener¬ 
ation plants fell naturally into two groups representing 25 and 75 per 
cent of the individuals seems conclusive proof that a single gene is largely 
responsible for the differentiation. Unlike most monohybrid characters, 
however, there is no single morphological characteristic that is predomi¬ 
nantly affected by this gene. At maturity the best pistillate inflorescence 
was harvested, and the various notes designed to measure the maize 
and teosinte characters were recorded. 
CHARACTERS MEASURED 
In the analysis of this hybrid 39 characters were studied, of which the 
means, standard deviations and probable errors are given in Table I for 
both the Fj and F 2 populations, and the frequency distributions for the 
F 2 population are shown in figures 1 to 39. 
DESCRIPTION OF CHARACTERS 
1. Height. —The height of the main culm is measured from the sur¬ 
face of the ground to the tip of the central spike of the tassel, and the 
measurements are recorded in decimeters. The average height of 
teosinte is 23 decimeters, of crinkly maize, 12 decimeters, of ramose 
maize, 18 decimeters, of brachytic maize, 9 decimeters. 
2. Height of tallest sucker. —The height of the tallest sucker is 
obtained and recorded in the same manner as that of the main culm. 
In teOsittte the tallest sucker is as high or higher than the central culm, 
While in the strains of maize used in these hybrids, suckers are produced 
but rarely, and they seldom are as tall as the main culm. 
3. Total sucker height. —The total sucker height is the summation 
of the heights of all the branches arising at or below the surface of the 
ground, and is recorded in meters. The total sucker height in teosinte 
usually is 20, while in the strains of maize used in these hybrids the total 
sucker height seldom exceeds one meter. 
4. Number of suckers. —The number of suckers is the total number 
of brandies arising at or below the surface of the ground. The number 
of suckers in teosinte is about 14, and in the strains of maize used in these 
hybrids the average number of suckers is less than 0.5. 
5. Leaves above.— Leaves above the uppermost branch of the main 
culm. This character corresponds to the number of nodes above the 
ear in maize. It is the number of leaves between the terminal inflores¬ 
cence and the uppermost lateral branch. In teosinte this is 1; in 
crinkly, ramose, and brachytic maize 5 or 6. 
6. Total number of leaves.— This character is the total number of 
leaves produced on the main culm from germination to maturity. About 
every fifth leaf is marked with small tags until the fifteenth, which is 
usually in good condition at maturity. Teosinte produces about 37 
leaves, and the maize parents about 20. 
7. Length of branching space. —This is the length in cm. of the 
branched portion of the terminal inflorescence of the main culm. In 
teosinte this measurement is about 7 cm., in crinkly maize 15 cm., in 
ramose maize 28 cm., and in brachytic maize 12 cm. 
