EYED HAWK-MOTH. 419 



may 6e is still a question. There are many pai'ts in many 

 animals which seem to serve no purpose, and are evidently the 

 rudiments of some organ which has not been developed. This 

 horn, however, is clearly not within this category, as it is far 

 too large and conspicuous not to be of real importance. At 

 first Fight it looks as if it were a weapon, but in the first place, 

 a caterjDillar needs no weapon, and in the second case, the horn 

 is incapable of being used as a weapon. Take any Hawk-Moth 

 caterpillar, and if roughl}^ handled it will twist itself about in 

 its efforts to escape, but it will not even attempt to pierce the 

 hand with its horn. And, even if it did wish to do so, the 

 position of the horn is about the worst that could be selected 

 for the purpose. There is no doubt that the formidable-looking 

 horn does deter ignorant people from touching the caterpillar, 

 but I cannot believe that so conspicuous an appendage was 

 given to the larva for so limited a purpose. 



All the caterpillars of the Hawk-Moths are prettily coloured, 

 while in some of them the hues may almost be termed brilliant. 

 In the present species the general colour is black, relieved by a 

 vast number of tiny white dots. The head is red, and a red 

 streak runs along the back from the head to the horn, the basal 

 part of which is red, the tip being black. The large spots 

 which are seen on the larva are whitish-grey, and beneath them 

 are smaller spots of the same red as that of the head. 



Owing to our limited space, we can but casually glance at 

 some other British Hawk-Moths. There is, for example, the 

 Eyed Hawk-jNIoth {Smerinthus ocellatus), so conspicuous by 

 the large eyelike spots in the middle of the lower wings, and 

 the beautiful pink-brown of the upper wings. The larva of 

 this Moth has a very rough skin, is pale-green in colour, 

 speckled with white, and has seven diagonal stripes on each 

 side of the body. The horn is blue. 



Then there is the less conspicuous, but really beautiful. 

 Poplar HAWK-iNIoTH {Smerinthus populi), so common in the 

 summer, clinging to the bark of trees, to rough posts, and 

 other objects which somewhat resemble it in general colour. 

 It may be known by the mottled brown of the upper wings, 

 with a wlii'ie spot in the middle, and the warm chestnut at the 

 base of the !ower wings. The caterpillar is rough, like that of 



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