PREFACE. IX 



terflies is due not so much to insufficient knowledge of their early stages 

 as to insufficient attention to what is actually known and published regard- 

 ing them. The principal modifications in that structure must now come 

 from a consideration of the earlier stages; and though Denis and Schiffer- 

 miiller, in their classical work on Vienna Lepidoptera, long ago wrote," Ein 

 Aug auf dem Schmetterling, das andere auf die Raupen, so werden alle 

 Schwierigkeiten gehoben," it may fairly be doubted whether one in ten of 

 those who, in the century that has elapsed since that was said, have dis- 

 cussed the classification of butterflies, have ever made the slightest exami- 

 nation of the newly-born caterpillar of a single butterfly, or could tell in 

 what points it differed from its own self at maturity. Yet no biologist will 

 dispute that the study of these earliest forms is at least of equal impor- 

 tance to the study of the mature caterpillar for any correct knowledge of 

 the phylogeny — and hence the classification — of butterllies. It is only the 

 closet naturalist, with whom the world is now done, that would hesitate. 

 The painful fact nevertheless remains that one may count on his two hands 

 the names of those in all the world who have ever contributed to a knowl- 

 edge of the structural characteristics of butterfly caterpillars at birth. 



It will be thought by many that some justification is needed for the 

 course adopted in subdividing the different groups more minutely than is 

 customary. To such I have only to say that if the characters I have 

 pointed out as pertaining to such groups and their relations to those 

 placed above and below them are not in themselves a justification, then 

 I have none, and no words of mine could or should alter such a fact; 

 if, however, these characteristics represent actual categories, and if at the 

 same time such groupings make clearer the relations which the life his- 

 tories and the distribution of the groups bear to their structure, then 

 words are not needed. 



On the other hand, I may be permitted to ask one question of such 

 complainants. If this minute subdivision did not affect the commonly 

 adopted scientific names of butterflies (as it does in many instances), 

 would any objection be raised or any justification be required ? If no 

 objection would be raised (and who believes there would?), then is all 

 this outcry against " fine-drawn distinctions " a mere quarrel about words 

 and names, into which, as quite too trivial, I decline to enter. Call things 

 by what names one will, I only ask that the facts of nature be rightly 

 interpreted; and where differences are found, that they be given their 

 proper values as nearly as we can determine them, absolutely regardless 

 of the effect it is to have upon the paltry question of names. Names can 

 never have absolute fixity until we have absolute knowledge of all the 

 facts regarding the creatures they represent, and the sooner this truth 

 is recognized the better for all concerned. 



I, for one, do not stand with those who claim that all our classifica- 

 tions are mere conveniences, momentary artificial strait-jackets for a 

 redundant and irrepressible Nature. In so far as they do not represent 



