n 4 SIR WILLIAM FLOWER CHAP. 



be of no inconvenience to the animal, one can imagine rudiments 

 of the proximate bones remaining for a very long time after they 

 had become functionless, as in the whalebone whales. 



These animals are full of points of interest, and furnish more 

 arguments than any I know for the theory of transmutation. 



THE DUKE OF ARGYLL TO PROFESSOR FLOWER 



June II, 1883. 



I am very glad if my questions have directed your attention 

 with definite results to the curious problem as to the prospective 

 or retrospective character of rudimentary organs in the Cetacea 

 as well as in other animals. 



I am not sure that I quite understand your argument. But 

 it will be best understood by seeing specimens, and I should be 

 very glad some of these days to attend at the Museum and see 

 any that you could show me. 



In the processes of ordinary generation it is quite clear that 

 the future organs must be in the germ, and must in time have 

 incipient parts, whether they are visible or not. Transmutation 

 involves the supposition that the whole line of future development 

 must be similarly present in all germs potentially at least with 

 beginnings of actual structure, visible at certain times. A priori, 

 therefore, one would expect such structures to appear in any 

 complete series of organisms. If they do not appear, I suppose 

 we must take refuge in that convenient " bolt-hole " the " Im- 

 perfection of the Record." 



That all limbs should begin with integumentary foldings, 

 unsupported by any internal structure, seems very strange. 



THE DUKE OF ARGYLL TO PROFESSOR FLOWER 



June 30, 1883. 



I have read with great care your most interesting lecture, so 

 far as published [the lecture on " Limbs "] . 



I see that the principle for which I am looking as probably 

 to be found in Biology is virtually involved in a fact which has 

 long been recognised in Comparative Anatomy, and which you 

 specially dwell upon as exemplified in the whales. That fact 



