INTRODUCTION 27 



enquiry with which I am even slightly acquainted 

 which presents so many pitfalls as the interpretation 

 of natural contrivances. I have learnt by sad ex- 

 perience to believe that my own first attempts to 

 interpret a new structure are nearly always wrong, 

 and it would not be hard to show that some very 

 eminent naturalists have had an experience not 

 altogether unlike mine. The only remedy is to be 

 patient, and to go on working until your explanation 

 has stood the test of time and wider experience. 

 Above all, do not print anything the moment you 

 have come to believe in it. When you have done 

 your utmost, you have not taken away the possibility 

 of being seriously wrong, but to print in haste is to 

 invite disaster. 



This is a discouraging reflection, and may lead 

 some to prefer studies where surer if less interesting 

 results are to be won. But it will never do to turn 

 away from the interpretation of natural contrivances 

 merely because the task is difficult and risky. This 

 is one of the permanent interests of mankind ; to 

 know how the wonderful adaptations of plants and 

 animals came into existence, and what purposes they 

 serve, is the great aim of the study of Nature. And 

 experience shows that though many investigators fail 

 at times, and though some fail altogether, substantial 

 progress is made in nearly every generation. We now 

 know much more about natural contrivances than 

 was known before Charles Darwin, and almost in- 

 finitely more than was known to Swammerdam or 

 Leeuwenhoek. 



