. Genetics in relation to agriculture. Livestock; Heredity; Variation (Biology); Plant breeding. INDEPENDENT MEN DELI AN INHERITANCE 79 of these observations, particularly with respect to that pair of characters concerned with cotyledon color. Johannsen has summarized these results and examined them with reference to their agreement with the conditions imposed by the laws of chance. Table VIII which has been adapted from Johannsen shows that in a sum total of 179,.399 counts by seven different investigators the ratio was The probable error for this number of observations is + 0
. Genetics in relation to agriculture. Livestock; Heredity; Variation (Biology); Plant breeding. INDEPENDENT MEN DELI AN INHERITANCE 79 of these observations, particularly with respect to that pair of characters concerned with cotyledon color. Johannsen has summarized these results and examined them with reference to their agreement with the conditions imposed by the laws of chance. Table VIII which has been adapted from Johannsen shows that in a sum total of 179,.399 counts by seven different investigators the ratio was The probable error for this number of observations is + so that the deviation from the ideal ratio is slightly greater than the probable error, but only so great that such a deviation would be expected approximately twice in five times. Another case which has been investigated with very large numbers is that of the contrasted characters starchy and sweet endosperm in •^^"'x. Fig. 37.—Results of crossing starchy and sweet corn: a, Sweet parent; c, starchy parent; 6, the Fi showing complete dominance of starchiness; d, the Fz showing monohjfbrid segregation; e, /, g, and h, Fs populations, the last three obtained by planting F2 starchy grains, the sweet ear, e, by planting an F-2 sw^eet grain, {After East and Hayes.) maize. Those varieties of maize which have starchy endosperms have smooth opaque grains whereas the varieties with sweet endosperms have translucent, wrinkled grains. The difference is due to the fact that in ripening there is a progressive formation of starch in starchy races, but in sweet races the starch grains formed are small and angular and there is an actual breaking down of endosperm materials into various kinds of sugars. Correns has shown that starchiness is completely dominant and segregation is sharp and unquestionable aside from very exceptional cases of intergrading. Fig. 37 illustrates very well how sharply segre- gation occurs in hybrid ears. The results of East and Hayes' extensive investig
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