102 ANIMAL COLORATION. 



world. I need only refer to the classical instance of the New 

 Zealand Parrot, which has, in the last fifty years, taken to a 

 purely carnivorous living. Caterpillars often feed upon many 

 different plants; the Gooseberry caterpillar will eat almost any 

 shrub, including laurel ; and I have " beaten " the larva? of 

 JXotodonta trepida from both oak and beech in the New 

 Forest. A change from shrubs to grasses may therefore have 

 been found necessary by the larva? of these Satyrida? ; those 

 that remained upon the shrubs were decimated by birds, while 

 those that dropped on to the grass underneath and stayed there, 

 survived in greater numbers ; thus the habit might be in- 

 herited. Among the thick-bodied night-flying moths the 

 Noctua? there are many genera in which the larva? are 

 invariably striped, and as invariably feed upon the tissues of 

 reeds, grasses, and other low-growing plants. I have already 

 mentioned the genera, the larva? of all the species of which in 

 this country are striped. This again looks like a race character, 

 independent of selection, but there is still the coincidence 

 between colour and surroundings. It must be remembered, 

 however, that there is nothing peculiar in longitudinal striping; 

 the patterns of coloration among animals are limited to very 

 few types; we have spots, cross stripes, and longitudinal stripes 

 turning up in all orders. There are longitudinally-striped 

 quirrels, just as there are longitudinally-striped caterpillars. 

 If there were something unique and remarkable in the colora- 

 tion, more stress might be laid upon the resemblance to 

 grasses. Most of these caterpillars, however, are night-feeders, 

 and a large number hide themselves during the day; it may be 

 suggested that they begin to feed early in the evening, when 

 their colours, if conspicuous, would be readily seen. If this is 

 so, it does not much matter, for the birds would, the bulk of 

 them at any rate, have gone to roost. 



