Translator's Preface. xi 



the origin of the markings of caterpillars. A 

 most valuable method of research is thus opened 

 up, and entomologists should not be long in 

 availing themselves of it. Our knowledge of the 

 subject of larval development in Lepidoptera 

 is still most imperfect, and it cannot as yet be 

 foreseen to what extent the existing notions of 

 classification in this much-studied order may have 

 to be modified when a minute study of the Com- 

 parative Ontogeny of larval characters, worked out 

 as completely as possible for each family, has 

 enabled a true genealogical system to be drawn 

 up. The extent to which such a larval genealogy 

 would coincide with .our present classification 

 cannot now be decided, but he who approaches this 

 fruitful line of inquiry in the true spirit of an investi- 

 gator, will derive much instruction from Prof. 

 Weismann's remarks on " Phyletic Parallelism in 

 Metamorphic Species." The affinities of the 

 larger groups among Lepidoptera would most 

 probably be made out once and .for ever if 

 systematists would devote more time to observa- 

 tion in this field, and to the co-ordination and 

 working up of the numerous data scattered 

 throughout the vast number of entomological 

 publications. 



The doctrine of development by no means 

 implies, as has sometimes been maintained, a 

 continuous advancement in organization. Al- 

 though the scale of organic nature has continued 



