FOREWORD 



in order that the reader may understand the various angles of the case. 



It is thus desired to emphasize the fact that the present report is 

 more purely philosophical in character than would be justifiable in 

 almost any other branch of mammalogy. We really know so little re- 

 garding the multitude of unique aquatic specializations that were state- 

 ments confined to proven facts the most interesting parts of this fascinat- 

 ing topic would be omitted. 



In formulating theories and endeavoring to interpret conditions I 

 have taken frequent opportunity to discuss problems with my colleagues. 

 Often have they made remarks and offered suggestions that have given 

 me an entirely new angle from which to approach some particular de- 

 tail. For this I am appropriately grateful, and although I have tried 

 always to make acknowledgement at the proper place, still I have found 

 it difficult to give stated credit where credit may really be due. I can 

 and do, however, give full measure of appreciation to Remington Kel- 

 logg, whose unflagging interest in my undertaking and broad knowledge 

 of whales, unstintedly shared, have proven quite indispensable. 



