between lepidopterous larve and their surroundings. 327 
XIII, XIV, as well as VA in the first series of experiments), 
they were tied together in pairs with the lichen-covered 
surfaces outwards. 
EXPERIMENTS XVI, XVII, anp XVIII with THE LaRvz 
OF O. BIDENTATA UPON GREEN LEAVES AND SHOOTS 
OF THE FOOD-PLANT (Populus nigra). 
The results of these experiments were uniform, and 
require so little description that a tabular form of 
presentation is unnecessary. 
Experiments XVI (10 young larvee), XVII (17 larvee), 
and X VITI (14 larvae) were begun by Mr. Holland on August 
3rd, 1893. He recorded that the larvee of XVI were pale 
brown, 2 of them rather variegated; while of XVII, 14 
were pale brown and 3 rather variegated. Of XVIII no 
record was made. ‘The larvae were the last hatched from 
the mixed batch of eggs which supplied the material for 
Experiments X to XV. 
August 8th. All re-fed. Sixteen larvee in XVII. 
August 12th, XVI and XVIII re-fed ; the latter noted 
as nearly all pale brown, a few rather variegated. 
August 15th and 19th. XVI and XVIII re-fed; larvae 
10 and 14 respectively. 
August 17th. XVII re-fed; 16 larve. 
August 21st. XVII re-fed; 8 larvze had escaped. The 
10 larvee in XVI were all of a pale brown colour. 
August 22nd. XVIII, 13 larvee pale brown, 1 darker 
with a few green markings. 
August 26th and 31st. All re-fed; larvee 10, 8, and 14 
respectively. 
September 5th. XVI, becoming mature (2 still feeding 
on 9th and 13th; no further notes on this set). XVII, 7 
larvee, all pale brown. XVIII, 14 larve. 
September 8th. XVII, 2 mature (all mature on 13th). 
XVIII, 1 mature, 1 dead. Of 12 still feeding, 10 pale 
brown, 2 rather darker brown. Two out of the 12 slightly 
tinged with green. 
September 13th. XVIII, 6 still feeding. On the 
18th they were neither pupating nor feeding, and on the 
23rd the last died. It appears possible that there was 
a tendency towards hybernation on the part of the larve 
with the slowest rate of growth. 
