Heredity and sex . F Seeds in Any One Capsule Average No. OF Seeds per Capsule Long-styled form bypollen of short-styled form:Legitimate union. 10 6 62 34 Long-styled form byown-form pollen:Illegitimate union. 20 4 49 2 Short-styled form bypollen of long-styled form:Legitimate union. 10 8 61 37 Short-stjded form byown-form, pollen:Illegitimate union. 17 3 19 9 The two legitimateunions together. 20 14 62 34 The two illegitimateunions together. 37 7 49 2 We know now that these two types of plants — long-styled and short-styled — differ from each other bya single Men
Heredity and sex . F Seeds in Any One Capsule Average No. OF Seeds per Capsule Long-styled form bypollen of short-styled form:Legitimate union. 10 6 62 34 Long-styled form byown-form pollen:Illegitimate union. 20 4 49 2 Short-styled form bypollen of long-styled form:Legitimate union. 10 8 61 37 Short-stjded form byown-form, pollen:Illegitimate union. 17 3 19 9 The two legitimateunions together. 20 14 62 34 The two illegitimateunions together. 37 7 49 2 We know now that these two types of plants — long-styled and short-styled — differ from each other bya single Mendelian factor. We may therefore state 202 HEREDITY AND SEX Darwins result in more general terms. The hetero-zygous plant is more vigorous than the homozygousplant. Moreover, in this case it is not the presenceof the dominant factors that makes greater vigor (forthe short-styled plant containing both dominants isless vigorous than the heterozygous), but the presenceof two different factors that gives the Fig. 97. — At left of figures there are two strains of pure bred corn andat right the hybrids produced by crossing those two pure strains. (AfterEast.) The most thoroughly worked out case of the effectsof inbreeding and cross-breeding is that of Indian recent years East and G. H. Shull have studied ona very large scale and with extreme care the problemin this plant. Their results are entirely in accord onall essential points, and agree with those of Collins,who has also worked with corn. East and Shull find that when two strains of corn FERTILITY 203 (that have been to a large extent made pure) are crossed,the offspring is more vigorous than either parent (Fig.
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Keywords: ., boo, bookcentury1900, bookdecade1910, booksubjectsex, bookyear1913
