452 CONCLUDING REMARKS. 



Third; In the fact that where a variety has all of the 

 positive features of its species ; or, where it possesses 

 all of the positive features which characterize the other 

 varieties of the species, no advantage accrues from its 

 -crossing with another variety. 



To these proofs and evidences, has been added the 

 following, which' sets an effectual bar to the admixt- 

 ure of distinct species, and shows that there exists " a 

 broad and insuperable distinction between varieties or 

 races and species :" 



23. Species when crossed, are either sterile them- 

 selves, or produce offspring which are sterile. 



The obvious and even the admitted import of this 

 phenomenon is diametrically opposed to Darwin's 

 theory. Darwin, however, has attempted two hypoth- 

 eses, with which to obviate the force of this objection 

 to his theory. These wholly fanciful hypotheses of his 

 are not only susceptible of signal confutation, but the 

 one, viz., that even individuals of the same species are 

 susceptible of all degrees of lessened fertility and ste- 

 rility, and that therefore sterility is not distinctive of 

 species ; and the other, viz., that this sterility subsist- 

 ing between different species, may not be a special en- 

 dowment, but may have been induced by modifications 

 ■ slowly impressed by unknown means, on the reproduc- 

 tive systems of the parent forms ; recoil with ten-fold 

 force upon him and his theory, and disclose the full 

 extent of the significance with which the sterility of 

 hybrids is fraught. 



The phenomena, of lessened fertility among individ- 

 uals of the same species, to which he appeals, show 



