224 Retrograde Varieties 



various facts, given in former lectures and how 

 it may be of use in our further discussions. 



It is obvious that the differences between ele- 

 mentary species and varieties on the one hand, 

 and between the positive and negative varieties 

 as distinguished above, are quite comparable 

 with our theoretical views. For we have seen 

 that varieties can always be considered as hav- 

 ing originated by an apparent loss of some 

 quality of the species, or by the resumption of 

 a quality which in allied species is present and 

 visible. In our exposition of the facts we have 

 of course limited ourselves to the observable 

 features of the phenomena without searching 

 for a further explanation. For a more com- 

 petent inquiry however, and for an understand- 

 ing of wider ranges of facts, it is necessary to 

 penetrate deeper into the true nature of the im- 

 plied causes. 



Therefore we must try to show that elemen- 

 tary species are distinguished from each other 

 by the acquisition of new qualities, and that 

 varieties are derived from their species either 

 by the reduction of one or more characteristics 

 to the latent state, or by the energizing of dor- 

 mant characters. 



Here we meet with a great difficulty. Hither- 

 to varieties and subspecies have never been 

 clearly defined, or when they have been, it was 



