334 SUDDEN APPEAMANCE OP 



transmutation of species. If numerous species, belonging 

 to the same genera or families, have reall}^ started into life 

 at once, the fact would be fatal to the tlieory of evolution 

 tlirough natural selection. For the development by this 

 means of a group of forms, all of which are descended from 

 some one progenitor, must have been an extremely slow 

 process; and the progenitors must have lived long before 

 their modified descendants. But we continually overrate 

 the perfection of the geological record, and falsely infer, 

 because certain genera or families have not been found be- 

 neath a certain stage, that they did not exist before that 

 stage. In all cases positive palaeontological evidence may 

 be implicitly trusted; negative evidence is worthless, as 

 experience has so often shown. We continually forget how 

 large the world is, compared with the area over which our 

 geological formations have been carefully examined; we 

 forget that groups of species may elsewhere have long 

 existed, and have slowly multiplied, before they invaded 

 the ancient archipelagoes of Europe and the Unites States. 

 We do not make due allowance for the intervals of time 

 which have elapsed between our consecutive formations, 

 longer perhaps in many cases than the time required for 

 the accumulation of each formation. These intervals will 

 have given time for the multiplication of species from some 

 one parent-form: and in the succeeding formation, such 

 groups or species will apjoear as if suddenly created. 



I may here recall a remark formerly made, namely, that 

 it might require a long succession of ages to adapt an or- 

 ganism to some new and peculiar line of life, for instance, 

 to fly through the air; and consequently that the transi- 

 tional forms would often long remain confined to some one 

 region; but that, when this adaptation had once been 

 effected, and a few species had thus acquired a great ad- 

 vantage over other organisms, a comparatively short time 

 would be necessary to produce many divergent forms, 

 which would spread rapidly and widely throughout the 

 world. Professor Pictet, in his excellent Review of this 

 work, in commenting on early transitional forms, and 

 taking birds as an illustration, cannot see how the succes- 

 sive modifications of the anterior limbs of a supposed pro- 

 totype could possibly have been of any advantage. But 

 look at the penguins of the Southern Ocean; have not 



