178 THE ORIGIN OF SPECIES 



tion. Lastly, Saint-Hilaire found toward the southern extreme of 

 the range of Gomphia oleseformis two forms which he did not at 

 first doubt were distinct species, but he subsequently saw them 

 growing on the same bush; and he then adds, "Voila done dans 

 un meme individu des loges et un style qui se rattachent tantot 

 a un axe verticals et tantot a un gynobase." 



We thus see that with plants many morphological changes may 

 be attributed to the laws of growth and the interaction of parts, 

 independently of natural selection. But with respect to Nageli's 

 doctrine of an innate tendency toward perfection or progressive 

 * 1 development, can it be said in the case of these strongly pro- 

 nounced variations, that the plants have been caught in the act 

 of progressing toward a higher state of development? On the 

 contrary, I should infer from the mere fact of the parts in question 

 differing or varying greatly on the same plant, that such modifica- 

 tions were of extremely small importance to the plants themselves, 

 of whatever importance they may generally be to us for our 

 classifications. The acquisition of a useless part can hardly be said 

 to raise an organism in the natural scale; and in the case of the 

 imperfect, closed flowers, above described, if any new principle 

 has to be invoked, it must be one of retrogression rather than of 

 progression; and so it must be with many parasitic and degraded 

 animals. We are ignorant of the exciting cause of the above speci- 

 fied modifications; but if the unknown cause were to act almost 

 uniformly for a length of time, we may infer that the result would 

 be almost uniform; and in this case all the individuals of the 

 species would be modified in the same manner. 



From the fact of the above characters being unimportant for 

 the welfare of the species, any slight variations which occurred 

 in them would not have been accumulated and augmented through 

 natural selection. A structure which has been developed through 

 long-continued selection, when it ceases to be of service to a 

 species, generally becomes variable, as we see with rudimentary 

 organs; for it will no longer be regulated by this same power of 

 selection. But when, from the nature of the organism and of the 

 conditions, modifications have been induced which are unim- 

 portant for the welfare of the species, they may be, and apparently 

 often have been, transmitted in nearly the same state to numerous, 

 otherwise modified, descendants. It cannot have been of much im- 

 portance to the greater number of mammals, birds, or reptiles, 

 whether they were clothed with hair, feathers, or scales; yet hair 

 has been transmitted to almost all mammals, feathers to all birds, 

 and scales to all true reptiles. A structure, whatever it may be, 



