24 ANIMAL COLORATION. 



between the dorsal middle line and the spiracles, from the 

 horn to the head ; while the horn developed a patch of red at 

 the base. A little later a rudiment of the eye -spots appears 

 as a slight curved indentation of the subdorsal white line on 

 the fourth and fifth segments ; at this period a second white 

 line connecting the spiracles is evident. 



After the second moult the concavities on the subdorsal line 

 are filled in by a deposition of black pigment, the spiracnlar 

 white line disappears, and the subdorsal line becomes indistinct. 



After the third moult the eye-spots become extremely con- 

 spicuous, the general green coloration is no longer so uniform, 

 bat darker green sinuous striations are shown upon a lighter 

 ground. 



The fourth moult ushers in some important changes. The 

 general colour has changed to dark brown, the striations 

 being yellowish ; the subdorsal line only persists on the three 

 front segments and on the eleventh ; the red at the base of the 

 horn has entirely vanished, and that appendage has acquired a 

 greenish colour. There are a series of stripes, first visible in 

 the last stage, arranged obliquely on the spiracles. 



In the last stage the eye-spots of the fourth and fifth 

 segments repeat themselves on the subsequent segment ; they 

 are, however, merely black spots without the white and violet 

 " pupil " ; a pair of small, light-coloured dots also make their 

 appearance on each of segments 5 11. The remains of the 

 .subdorsal line on the first three segments is very evident as a 

 white line edged with black. 



We may thus distinguish a number of well-marked charac- 

 teristics occurring at different periods of life. The young 

 caterpillar is green, with no markings. In the next stage it is 

 furnished with longitudinal stripes. Finally it becomes brown, 

 and the longitudinal stripes have disappeared, except on the 



