x PREFACE 



at all events at present, an insignificant physiological interest. In making 

 this statement, it is far from my intention to undervalue in any way the 

 work of the organic chemist or the morphologist. Structure is the indispens- 

 able basis of function, and all structures, chemical or morphological, will, 

 IK i doubt, ultimately have their function assigned. But, in these pages, 

 space cannot be spared for description of such as have no functional 

 importance suggested up to the present. 



The treatment of the subject in the way here attempted undoubtedly 

 has its difficulties. Important points have most probably escaped reference. 

 I shall be very grateful to readers who will inform me of these omissions, 

 and also for criticism in general. I feel that I may, in some places, perhaps, 

 have laid myself open to the charge of neglecting statements which are 

 in opposition to the }>oint of view adopted. I consider myself justified in 

 certain instances in doing this, on account of the disagreement of these 

 statement* with a large mass of knowledge otherwise obtained, ami in tin- 

 belief that further investigation will explain the apparent contradiction. 

 As Sir Thomas Browne says (1672, vol. i. p. 115): "For what is worse" 

 (that is, than new knowledge being but reminiscence), "knowledge is niailc 

 by oblivion, and to purchase a clear and warrantable body of Truth, we 

 must forget ami part with much we know. Our tender Enquiries taking 

 up Learning at large, and together with true and assured notions, receiving 

 many, wherein our reviewing judgments do find no satisfaction." In 

 other cases of omission, my ignorance must serve as an excuse. But, as 

 Bacon has well pointed out, truth is more likely to come out of error, if 

 this is clear and definite, than out of confusion, and my experience teaches 

 me that it is better to hold a well-understood and intelligible opinion, even 

 if it should turn out to be wrong, than to be content with a muddle-headed 

 mixture of conflicting views, sometimes miscalled impartiality, and often 

 no better than no opinion at all. One is tempted to quote Browning: 



" Stake your counter as boldly every whit, 

 Venture as warily, use the same skill, 

 Do your best, whether winning or losing it, 



If you choose to play ! is my principle. 

 Let a man contend to the uttermost 

 For his life's set prize, be it what it will ! 



The counter our lovers staked was lost 



As surely as if it were lawful coin : 



And the sin I impute to each frustrate ghost 



Is the unlit lamp and the ungirt loin, 

 Though the end in sight was a vice, I say, 

 You of the virtue (we issue join) 

 How strive you? De te,fabida" 



(" The Statue and the Bust "last lines.) 



But, at the same time, there must never be the least hesitation in giving up 

 a position the moment it is shown to be untenable. It is not going too far to 

 say that the greatness of a scientific investigator does not rest on the fact of 



