The Origin of Species by Means of Natural Selection; Or, the Preservation of Favored Races in the Struggle for Life ...A.L. Burt, 1890 - 538페이지 |
도서 본문에서
23개의 결과 중 1 - 3개
285 페이지
... produced , up to nearly complete or even quite complete fertility ; and , as we have seen , in cer- tain abnormal cases , even to an excess of fertility , beyond that which the plant's own pollen produces . So in hybrids ... hybrids OF FIRST ...
... produced , up to nearly complete or even quite complete fertility ; and , as we have seen , in cer- tain abnormal cases , even to an excess of fertility , beyond that which the plant's own pollen produces . So in hybrids ... hybrids OF FIRST ...
288 페이지
... hybrids , though externally so like one of their pure parent - species , are with rare excep- tions extremely ... produced from this cross ; that the fertility of hybrids is not related to the degree in which they resemble in external ...
... hybrids , though externally so like one of their pure parent - species , are with rare excep- tions extremely ... produced from this cross ; that the fertility of hybrids is not related to the degree in which they resemble in external ...
307 페이지
... hybrids from long cultivated plants are more subject to reversion than ... produced from nearly related species , follow , according to Gärtner , the ... produced from a reciprocal cross generally resemble each other closely , and so it ...
... hybrids from long cultivated plants are more subject to reversion than ... produced from nearly related species , follow , according to Gärtner , the ... produced from a reciprocal cross generally resemble each other closely , and so it ...
기타 출판본 - 모두 보기
자주 나오는 단어 및 구문
adapted admit affinities allied species America ancient appear Asa Gray beak become bees believe belonging birds breeds cause cells characters climate closely allied color continued crossed crustaceans degree developed difficulty distinct species domestic doubt effects eggs embryo existing extinct extremely facts favorable females fertility flowers formation forms fossil Fritz Müller genera genus geological geological period gilt top Glacial period gradations greater number groups of species habits Hence hybrids hybrids produced important individuals inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ larvæ less living male mammals manner marsupials migration modified descendants natural selection naturalists nearly nest oceanic islands offspring organs parent peculiar perfect pigeons pistil pollen present principle probably produced quadrupeds ranked remarked resemblance rudimentary seeds sexual selection Silurian slight South America stamens sterility structure successive suppose tend theory tion variability variations varieties vary whole widely different wings young