inviableadj.

1918 Genetics 3 476 The disadvantage of so many individuals being rendered sterile or inviable.

1929 Encycl. Brit. XI. 495/1 In this case the F₂ generation, and the results of back-crossing F₁ to either parent, are usually polymorphic, and may include monstrous or more or less inviable forms.

1946 Nature 12 Oct. 520/2 Among 986 seeds collected in 1941 from chimeral plants there were found six triploid ones, three of which proved inviable.

1948 Mind 57 297 He found that within one ‘species’ of frog..ranging from lat. 45° N. to 27° N. in the United States, representatives of the northern and southern ends of the range gave inviable hybrids, though parents not too far apart geographically gave normal development.

1955 New Biol. 19 21 More usually an unbalanced and inviable nucleus is formed [from an irregular mitosis] in which some chromosomes are represented twice, others once or not at all.

1956 Nature 31 Mar. 626/2 Damage arising from inviable recombinations of broken chromosome ends.

1962 Lancet 29 Dec. 1384/2 Since the O-sperm, if functional, leads to the Turner zygote which is in great deficit in the general population, it seems likely that O-sperm are inviable and that the Turners are due to a phenomenon other than fertilisation by O-sperm.

1918 Genetics 3 Index 614/2 Inviability.

1929 Encycl. Brit. XI. 495/1 The inviability of most gametic and zygotic combinations.

1972 W. V. Brown Textbk. Cytogenetics xiv. 204/2 In most interbreeding populations inversions are eliminated because of the numerous types of inviability they produce.