The intermixture of distinct species is guarded against by the aversion of the individuals composing them to sexual union, or by the sterility of the mule offspring. It does not appear that true hybrid races have ever been perpetuated for several generations,... The London Quarterly Review - Página 31850Vista completa - Acerca de este libro
| Sir Charles Lyell - 1832 - 368 páginas
...least possible excess beyond the defined limits being fatal to the existence of the individual. Sthly. The intermixture of distinct species is guarded against...relate to the crossing of mules with individuals of pure species, and not to the intermixture of hybrid with hybrid. 6thly. From the above considerations,... | |
| Benjamin Godwin - 1834 - 314 páginas
...possible excess beyond the defined limits being fatal to the existence of the individual. " oth ly, The intermixture of distinct species is guarded against...relate to the crossing of mules with individuals of pure species, and not to the intermixture of hybrid with hybrid. "6thly, From the above considerations,... | |
| Sir Charles Lyell - 1837 - 568 páginas
...least possible excess beyond the defined limits being fatal lo the existence of the individual. Sthly. The intermixture of distinct species is guarded against...perpetuated for several generations, even by the assistance * E. R- A. Serres, Anatomic Compare du Cerveau, illustrated by numerous plates, tome i., 1824. of man... | |
| 1850 - 600 páginas
...improvement or deterioration, being prevented, and the least excess beyond the defined limits being fatal to the existence of the individual. " 5th. The intermixture...the crossing of mules with individuals of the pure species, and not to the intermixture of hybrid with hybrid. " 6th. From these considerations it appears... | |
| William Gifford, Sir John Taylor Coleridge, John Gibson Lockhart, Whitwell Elwin, William Macpherson, William Smith, Sir John Murray IV, Rowland Edmund Prothero (Baron Ernle) - 1850 - 612 páginas
...improvement or deterioration, being prevented, and the least excess beyond the defined limits being fatal to the existence of the individual. ' 5th. The intermixture...the crossing of mules with individuals of the pure species, and not to the intermixture of hybrid with hybrid. ' 6th. From these considerations it appears... | |
| 1850 - 608 páginas
...least excess beyond the defined limits being fatal to the existence of the individual. 1 ."•!•!. The intermixture of distinct species is guarded against...the crossing of mules with individuals of the pure species, and not to the intermixture of hybrid with hybrid. ' 6th. From these considerations it appears... | |
| John Holmes Agnew, Walter Hilliard Bidwell - 1850 - 604 páginas
...improvement or deterioration, being prevented, and the least excess beyond the defined limits being fatal to the existence of the individual. " 5th. The intermixture...sterility of the mule offspring. It does not appear tiiat true hybrid races have ever been perpetmted for several generations, even by the assistance of... | |
| 1857 - 520 páginas
...possible excess beyond the defined limits being fatal to the existence of the individual. " 5thly. The intermixture of distinct species is guarded against...relate to the crossing of mules with individuals of pure species, and not to the intermixture of hybrid with hybrid. "6thly. From the above considerations,... | |
| Thomas Ragg - 1858 - 456 páginas
...least possible excess beyond the defined limits being fatal to the existence of the individual. "5thly. The intermixture of distinct species is guarded against...of man ; for the cases usually cited relate to the crossings of mules with individuals of pure species, and not to the intermixture of hybrid with hybrid.... | |
| Maine. Board of Agriculture - 1859 - 552 páginas
...regard to the reality of species in nature ;" the following being a part of the fifth : (Ibid p. 589.) " It does not appear that true hybrid races have ever...relate to the crossing of mules with individuals of pure species, and not to the intermixture of hybrid with hybrid." Again Dr. Browne argues against crossing... | |
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