THE MADEIRA BEETLES— CONCLUSION. 377 



those which do not comply with the conditions ; if 

 there is nothing to render such and such a course a 

 sine qua non for life, there is no condition of existence 

 in respect of this course, and no modification according 

 to Lamarck could follow, as there would be no changed 

 distribution of use. 



I think that if I were to leave this matter here 

 I should have said enough to make the reader feel 

 that Lamarck's system is direct, intelligible and suffi- 

 cient — while Mr. Darwin's is confused and confusing. 

 1 may however quote Mr. Darwin himself as throwing 

 his theory about the Madeira beetles on one side in a 

 later passage, for he writes : — 



" It is probable that disuse has been the main agent in 

 rendering organs rudimentary" or in other words that 

 Lamarck was quite right — nor does one see why if 

 disuse is after aU the main agent in rendering an organ 

 rudimentary, use should not have been the main agent 

 in developing it — ^but let that pass. " It (disuse) would 

 at first lead," continues Mr. Darwin, " by slow steps to ' 

 the more and more complete reduction of a part, until 

 at last it became rudimentary — as in the case of the 

 eyes of animals inhabiting dark caverns, and of the 

 wings of birds inhabiting oceanic islands, which have 

 seldom been forced by beasts of prey to take flight, 

 and have ultimately lost the power of flying. Again, 

 an organ useful under certain conditions, might become 

 injurious under others, as with the wings of beetles living 

 on small and exposed islands ;" * so that the rudimentary 

 condition of the Madeira beetles' wings is here set down 

 * < Origin of Species, p> 401i 



