226 Lilian J. Gould's experimeids 



Total results of experiment (not counting the five 

 removed) : — 



Colour. No. of larvjE. 



Light brown, faint dorsal lines ... ... 3 



Darker brown, distinct dorsal lines ... ... 3 



Dark brown, dark dorsal lines 1 



Total 7 



Cylinder 16. — July 29th. — I placed five larvpe from 

 cylinder 11 in cylinder 16, still giving white sticks and 

 white willow. 



Aug. 1st. — The fourth ecdysis occurred. Three were 

 dark hrown and two light ; none were intermediate. 



Aug. 6th. — Three larvje died, two dark ones and a 

 light one. 



Aug. 13th. — A fourth larva died ; it was dark. 



Aug. 18th. — The last larva, a light one, died. 



Total results of experiment : — 



Colour. No. of larvre. 



Light brown, faint dorsal lines ... ... 2 



Dark brown, dark dorsal lines ... ... 3 



Total 5 



It will be seen from the above descriptions that none 

 of the larva} with green surroundings attained a green 

 colour, or even the slightest tinge of green — a change only 

 as yet known to be possible to a few species ; the change 

 consisted merely in their normal colour becoming lighter 

 or darker in depth, and the markings varying in the 

 degree of intensity. The difference between the most 

 extreme forms from dark and light surroundings was 

 striking, but the difference between those from green and 

 white surroundings slight, if any ; indeed, the extreme 

 light specimen figured came from green, not white sur- 

 roundings. The intermediate forms were very variable 

 in shade of ground colour, and also in depth of markings. 

 It is remarkable that in the larva3 of cylinder 8 the 

 colour-change bicame perceptible three days after the 

 first ecdysis, in the second stage of larval life, instead of 

 after the second ecdysis (the third stage) as was the 

 case in the others of C. nupta. 



