INTRODUCTORY. 27 



others stems or the bare surface of the earth ; it is simply a 

 new and better adaptation which has not yet thoroughly esta- 

 blished itself. The green caterpillars are to be looked upon 

 as individuals of a class that will ultimately disappear owing 

 to their retention of a less perfect form of adaptation. 



One difficulty in the way of this view of the origin of the 

 marking of the Hawk moth caterpillars is that the markings 

 are not always adaptive. With regard to the persistent reten- 

 tion of the longitudinal striping in the Macroglossinse (the 

 Humming-bird Hawk moth, Bee Hawk moth, etc.), Dr. 

 Weismann remarks that " it is not difficult to perceive how 

 a whole group could have made shift with this low grade 

 of marking [longitudinal striping] up to the present time. 

 Colour and marking are not the only means of offence and 

 defence possessed by these insects ; and it is just such simply- 

 marked larva? as those of the Macroglossinae which have the 

 protective habit of feeding only at night, and of concealing 

 themselves by day. Moreover, under certain conditions of life 

 the longitudinal stripes may be a better means of protection, 

 even for a Sphinx larva, than any other marking ; and all 

 those species in which this pattern is retained at the present 

 time live either among grasses or on Coniferse." 



This last statement is not absolutely true, since Macroglossa 

 fuciformis feeds upon honeysuckle, which, though it may 

 occasionally trail among grasses at the bottom of a hedgerow, 

 also climbs to a considerable height. It has longitudinal 

 stripes until an " advanced age." So far as the habit of night- 

 feeding is concerned, many of these larva? might have remained 

 in the first stage; for it would not matter what their colour was. 



But it may be always said that we have here an indication 

 of a former state of affairs; such an argument can no 

 refuted than those of the believers in Special Creation. 



