TRANSMUTABLE. 183 



prejudice,) must disappear from science, where it 

 lias so long been pre-eminent, constituting, as it 

 does, with several other propositions not less 

 contestable, what the partizans of the fixity of 

 species consider as the classical doctrine upon 

 hybrids. But in throwing aside this principle, 

 we must be very careful how we substitute for it 

 the contrary principle ; for if it is not certain 

 that hybrids are generally or imperfectly fertile, 

 still less can ice sustain that they are generally 

 calculated (aptes) to re-produce themselves. In 

 reality there is not here a fixed principle, but 

 only facts to ascertain, (constater,) and these facts 

 are very variable according to the species which 

 are under consideration" (Kevue et Magazin de 

 Zoologie, January, 1860, p. 40.) 



Now let me ask in all seriousness, if, according 

 to this result of the labours of perhaps the 

 greatest living authority upon the subject of 

 hybridism, any one is justified in inferring there- 

 from the identity of species and variation, and 

 from thence drawing a deduction in support of 

 a generalization of much greater magnitude and 

 importance? 



M. I. Geoifry St. Hilaire's experiments were 

 performed between animals of the same family as 

 the dog and the wolf, and the dog and the 

 jackal, and yet he cautions us, in unmistakable 

 language, not to apply the principle to the general 

 fertility of hybrids. Mr. Darwin, however, makes 

 it one of the chief pillars of his doctrine, and 

 is obliged to give it force by assuming that there 



