. Botany, with agricultural applications. Botany. MORE RECENT INVESTIGATIONS OF MENDELISM 551 mals. By working according to the Mendelian conception, many desirable varieties of the cereals, much more desirable ornamental plants, and various kinds of better fruits have been developed. Of course in the extended investigations in Genetics since 1900, many situations have arisen that Mendel did not meet. Cases have arisen in which the Mendelian behavior can be explained better by assuming that pairs of contrasting characters are due to the presence and absence of certain factors and not to domina
. Botany, with agricultural applications. Botany. MORE RECENT INVESTIGATIONS OF MENDELISM 551 mals. By working according to the Mendelian conception, many desirable varieties of the cereals, much more desirable ornamental plants, and various kinds of better fruits have been developed. Of course in the extended investigations in Genetics since 1900, many situations have arisen that Mendel did not meet. Cases have arisen in which the Mendelian behavior can be explained better by assuming that pairs of contrasting characters are due to the presence and absence of certain factors and not to dominant and recessive factors. According to the latter hypothe- sis, the tallness of the tall variety of Peas is due to the presence of a factor for tallness, while dwarfness in the dwarf variety is. Fig. 480. — Height of plants in the Fi generation of Tom Thumb Pop Corn (a dwarf Corn) crossed with Missouri Dent (a large Corn). The plant at the extreme right is similar in height to the dwarf parent, while the one at the extreme left is similar in height to the Missouri Dent. After Emerson and East. due to the absence of the factor for tallness. The presence and absence hypothesis explains some cases more satisfactorily than the dominant and recessive hypothesis. Again Mendel worked chiefly with qualitative characters, which have been found to behave differently from most qualitative characters, such as size and weight. For example, m crossing large and small varieties of Corn, the individuals of the first hybrid generation are intermediate in size between the parents, the size of. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Martin, John N. (John Nathan), b. 1875. New York, John Wiley & sons, inc. ; [etc. ,etc. ]
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectbotany, bookyear1920
