CHAPTER XXV 



CATERPILLARS 



'HIS is an immensely interesting branch of the subject.* The existence 



of most naked lepidopterous larvae is singularly dependent on protective 

 coloration, owing to the fact that they are the favorite prey of many kinds of 

 birds, and, living exposed to view on leaves, are also incapable of rapid motion. 

 This universality of the extreme need of concealing coloration among hairless, 

 leaf -eating larvae, and the enormous number of their species, whose many and 

 diverse food plants, feeding habits, sizes, and fundamental structural shapes 

 call for an almost equally great variety of devices for the achievement of their 

 protection, makes the study of them peculiarly fruitful, as well as intricate 

 and difficult. Indeed, the subject is so vast, that no one, even if he devoted 

 years exclusively to it, could hope to discover and appreciate more than a small 

 fraction of the whole number of diverse but equally fine and remarkable pro- 

 tective-coloration developments of the larvae of a single wooded region. 



In the plates which follow, we show merely the pick of a small collection of 

 paintings and sketches made during two autumns largely devoted to the study 

 of caterpillars (and spiders), chiefly in southwestern New Hampshire, U. S. A. 

 Few and imperfect though they are, they yet illustrate fairly well several princi- 

 ples which are of primary importance. We have confined ourselves almost 

 entirely to hairless larvae, because highly specialized protective coloration 

 plays a much larger part among them than among the hairy ones. This is 



* (Historically, it is especially noteworthy as being the branch in which Prof. Edward B. Poul- 

 ton, of Oxford University, made his independent and earlier partial discovery of the law of Oblit- 

 erative Shading. At the time, however, he did not realize that the law had a wide application, even 

 among lepidopterous larvae, and his subsequent original investigations of protective coloration have 

 been largely in the field of mimicry. See, however, the quotation from Nature at the close of our 

 first chapter.) 



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