146 Miss Elizabggle Bridges upon colour-relation between 
(f) Black twigs of oak with pink spots painted on 
them: bluish-black larvae. 
(g) Slips of white wood painted with scarlet squares 
(length of side about 2 mm.): cream-coloured larvae with 
faint smoky pattern (slightly darker than in (7)). 
It will be noticed that the twigs painted in geometrical 
patterns produced no corresponding effect. The results 
of all the experiments seem to show that although the 
individual larvae and pupae are able to conceal them- 
selves very effectually among surroundings to which the 
species is accustomed, they are powerless to effect any 
appropriate adaptation to an “artificial” environment. 
TABLE IV. 
Bis Be yg | 
S is 2 6 Qe om 
eeESa Ss 50 mi | 
a) a =e cay 
WHPE. ay Bug ei 
& oO z - a Zi AS { 
Ae ee Sens a 
Hae Ay |) Te tis D PUPAL COLOURS PRODUCED. | 
ema Pee He 
72OR ° o<s Zz | 
Aa me Qa Asa BQ | 
5 al tess A Bon p } = | 
FS --:-b=) 4 40o% | Fo | 
On8m | g | ee | SE 
ROm leo Hm | 
be < S = | #8 | 5 
Bs Role 
Black. | Bl. | Bl. — Bl. | 8 with not much cocoon, 3 in cocoon 
| of bits of leaf. All very dark brown 
| | _ smoked with black. 
Black. | Bl. Wh. BL | 2 in cocoons of laef, slightly less smok 
| ’ to} 
than the last set. 
Black. | Bl. | Wh. | Bl. | 2 no cocoon, 2 in leaf cocoons, These | 
| 4 of a uniform light reddish brown 
| | with very sparing black specks, 1 in 
| leaf cocoon, darkest form. | 
V. Notes on the apparatus used. 
The larvae were kept in clear glass cylinders or lamp 
shades, varying froin 8 to 10 inches in height, and from 
3 to 5 in diameter. The tops were covered by white 
muslin or calico. The floors were of wood covered with 
white paper: a hole in each floor allowed the stems of the 
food-plant to pass through into a jar of water. As the 
larvae became larger, some were transferred to other 
cylinders, so that they were never crowded. 
The pupae which were not left in their original environ- 
ments were tested in cardboard compartments (about 
