. Biology . an monk, in the gardens of the monastery at Brunn. Theresults of his experiments and the conclusions he drew fromthem were published in an obscure journal, where they remainedburied for thirty-five years. In the year 1900, the botanistsde Vries, Correns and Tschermak, working independently, eachbrought out evidence confirming Mendels conclusions, and thefull value of his work was finally recognized. Soon after,Bateson demonstrated that Mendels principles apply toanimals as well as plants. A. Heredity of One Pair of Characters.—Mendelsprinciples of heredity can be best illustrated b
. Biology . an monk, in the gardens of the monastery at Brunn. Theresults of his experiments and the conclusions he drew fromthem were published in an obscure journal, where they remainedburied for thirty-five years. In the year 1900, the botanistsde Vries, Correns and Tschermak, working independently, eachbrought out evidence confirming Mendels conclusions, and thefull value of his work was finally recognized. Soon after,Bateson demonstrated that Mendels principles apply toanimals as well as plants. A. Heredity of One Pair of Characters.—Mendelsprinciples of heredity can be best illustrated by a caseof his own, involving only one pair of characters, in which one 220 THE PERPETUATION OF ADAPTATIONS of the pair comes from the female parent, the other from themale. Mendel crossed two types of garden pea, one parentplant producing yellow peas, the other green peas. A hybrid(Fi generation) resulted from this cross, which produced onlyyellow peas. These yellow peas produced plants which were. Fig. 93.—Mendelian inheritance resulting from the crossing of yellow and greenpeas. (From Morgan,) then intercrossed or self-fertilized, and the resulting peas (F2generation) were found to be mixed, the pods containing bothyellow and green peas in the proportion of three yellow to onegreen (Fig. 93). These, in turn, were grown and again self-fertilized, when it was found that the green peas produced only MENDELIAX INHERITANCE 221 green peas, while the yellow peas were found to be different;some produced only yellow peas, while others produced yellowand green peas, again in the ratio of three to one. The pureyellow peas were found to be just one-third of the total numberof yellow peas produced, or one-quarter of the total numberof peas—thus, i green: 2 mixed, i yellow. In reasoning out the significance of his results, ^Mendel con-cluded that something is carried into the germ cells which pro-duces color in the seeds. One original parent contained a factorfor yellow, the
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