454 CONCLUDING REMARKS. 



ological integrity, its fertility, and constitutional vigor ; 

 and fourthly, from the phenomena of the Sterility 

 of Species, or of their Hybrids which proves that 

 there is an insuperable bar to the admixture of the 

 species — do the facts converge to the following con- 

 clusions, viz. : 



That there is but one, normal mould or type for any 

 given species : 



That such normal type alone is consistent with 

 physiological integrity. 



That the several, existing varieties, or races, of any 

 given species, are but negative modifications, or seg- 

 ments of the proper type of such species : 



That any departure from the full, structural integrity 

 of the perfect type of the given species, is fraught with 

 proportional physiological evils : 



That any return towards the perfect type of the 

 given species, is attended with proportional abatement 

 of the physiological evils under which the individual 

 suffered : and 



That each species, although susceptible of countless 

 injurious modifications, is normally immutable. 



THE END. 



