58 THE ORGANIC GROWTH OF THE LIVING WORLD sec. 



the large conspicuous surface of the caterpillar's body into 

 several areas, and so made it less conspicuous." 



In fact, one has only to look at such a light green cater- 

 pillar with long stripes as it rests lengthwise on a grass-stalk 

 or a pine-needle. 



Weismann points out that all caterpillars of the Sphingidae, 

 in which the longitudinal striping is at the present time the 

 permanent marking, live either among grasses or on conifers. 



Oblique striping is regarded by him as adapted to the 

 veins of leaves, the circular or ocellus marking as imitating 

 parts of the plants fed u^^on, berries, etc., or as means of 

 frightening enemies, or as enabling the possessor to be recog- 

 nised as unpalatable. 



Preponderance of the males, I myself suggested further, 

 might be possibly explained by the fact that the males fight 

 the battle of existence more than the females, and therefore 

 must always be first to respond to new demands. The 

 postero-anterior evolution by the fact that the part of the 

 body farthest from the head is most in need of mimicry, 

 because it is least protected in other ways by the sense- 

 organs, and because it is at a special disadvantage ; that it is 

 the last part to be withdrawn from the pursuit of an enemy 

 (some instances of the opposite condition in caterpillars I 

 endeavoured to trace to special adaptations). The fact that in 

 mammals the new marking appears first on the sides was 

 comprehensible, I thought, because the sides were most 

 exposed to the view of an enemy, certainly more than the 

 markinsj alonoj the back, which alwavs remains at a lower 

 stage. 



" The preponderance of age," I said, " is due, in the first 

 place, to the fact that those individuals which are most 

 adapted to the environment as a rule also live longest, and 

 have the longest time to transmit their peculiarities. 



" Since, moreover, the individuals provided with the new 



