...to develop, but undoubtedly depending upon certain affinities, either structual or constitutional, there was a greater disposition to fertility in some...the whole belt of the globe, within the tropics and a certain distance from them, under a great variety of circumstances, affecting the constitution of...

...either could not be crossed at all or produced offspring which were sterile; and he thence concludes, "that the fertility of the hybrid or mixed offspring...the closer botanical affinities of the parents." The popular ideas as to the sterility of hybrids are derived from crosses between certain domestic animals...

...either could not be crossed at all, or produced offspring which were sterile ; and he thence concludes ' that the fertility of the hybrid or mixed offspring...than the closer botanical affinities of the parents.' " — (Wallace. Fortnightly Review, vol. xl., NS, p. 311.) Distinct families are fertile inter se....

...three years—nearly 87 per cent, t Dean Herbert says elsewhere : " Experiments have confirmed the view to such a degree as to make it almost certain that the fertilisation of the hybrid or mixed offspring depends more upon the constitution than the closer botanical...

...Herbert did not give cross fertility primacy over degree of morphological similarity since he believed "that the fertility of the hybrid or mixed offspring depends more upon the constitutional [whatever that means!] than the closer botanical affinities of the parents" (1837: 342). Not reproductive...