xxviii Preface to the English Edition. 



matters stood it was indispensable that the facts 

 should be examined into and established even 

 down to the most trifling details. The essay 

 "On the Origin of the Markings of Caterpillars" 

 especially, had obviously to commence with the 

 sifting and compilation of extensive morphological 

 materials. 



AUGUST WEISMANN. 



Freiburg in Baden, 



November ', 1881. 



