4 PROLEGOMENA 



therefore, to mention now what sections of the book could be said 

 to be most valuable to any student of general biology. Part i comes 

 in this class, and of Part iii, the middle portion of Section i, all of 

 Sections 2, 3, and 5, thelatter half of Section 7, Sections 8, 9 (especially 

 the end), 11, possibly 18, and finally the Epilegomena. 



For my models in the preparation of this book, if it is permissible 

 to name them, I have taken, Growth and Form by d'Arcy Thompson, 

 surely the most scholarly work produced by a biologist in our time, 

 and The Physiology of Reproduction by F. H. A. Marshall, already 

 mentioned, which showed to all successors, in my opinion, how a 

 colossal array of facts can be welded together into an absorbing and 

 readable book, I am conscious that I shall not attain the level of 

 these classics of modern biology, but then 



.... Pauci, quos aequus amavit 

 Jupiter, aut ardens evexit ad aethera virtus. 



The progress of any branch of natural knowledge can be best 

 described as a continual pilgrimage towards the quantitative. QuaUties 

 can never be altogether left out of account and this is what makes 

 it impossible for science to achieve its end with absolute finality. Yet 

 an association with the probably unattainable is common to all the 

 great types of man's activity. But "Fuyez toujours les a peu pres", 

 as O. W. Holmes used to put it, is a proper maxim for the scientific 

 mind, and whatever this book can do towards making embryology 

 an exact science will be its final justification. 



