n.] GHJEROCAMPA ELPENOR. 53 



again find species — for instance, LopKyrus socio, — which 

 live on the pine, and in which the same stylo of 

 colouring is repeated. 



Let us now take a single group, and see how far we 

 can explain its various colours and markings, and what 

 are the lessons which they teach us. For this purpose, I 

 think I cannot do better than select the larvae of the 

 Sphingidce, which have just been the subject of a mas- 

 terly monograph by Dr. Weismann, from whom most 

 of the following facts are taken. 



The caterpillars of this grqup are very different in 

 colour — green, white, yellow, brown, sometimes even 

 gaudy, varied with spotSj patches, streaks, and lines. 

 Now, are these differences merely casual and accidental, 

 or have they a meaning and a purpose ? In many, 

 perhaps in most cases, the markings serve for the 

 purpose of concealment. When, indeed, we see cater- 

 pillars represented on a white sheet of paper, or if we 

 put them on a plain table, and focus the eye on them, 

 the colours .and markings would seem, if possible, to 

 render them even more conspicuous ; as, for instance, in 

 Deilephila galii; but amongst the intricate lines and 

 varied colours of foliage and flowers, and if the insect be 

 a little out of focus, the effect is very different. 



Let us begin with the Chcerocarnpa elpenor, the 

 elephant hawk-moth. The caterpillars, as represented 

 in most entomological works, are of two varieties, most 

 of them brown (Fig. 46), but some green. Both have 

 a white line on the three first segments ; two remarkable 

 eye-like "spots on the fourth and fifth, and a very faint 

 median line ; and are rather more than four inches long. 

 I will direct your attention specially, for. the moment, to 



