176 CLUES AND SUGGESTIONS CHAP. 



of the vertebrate Plan from the beginning 

 of the series, for the very reason of its 

 potential adaptability to an immense 

 variety of purposes. Moreover, the 

 arrest of such tendencies of growth, at a 

 given point in the series, may well have 

 been part of the same Plan from the 

 beginning. But the survival of their 

 effects the traces of this method of 

 operation would thus be a perfectly 

 intelligible fact. 



As already said, the case which pre- 

 sents all these problems in the most 

 striking form is the case of the Whales, 

 and especially the case of that species 

 which, from the commercial products of 

 its organism, is most widely known. 

 Both the organs which in this creature 

 are present as rudiments alone, and those 

 which, on the contrary, are very highly 

 developed and most wonderfully special- 

 ised, are equally significant. Constructed 



