366 Proceedings of the Royal Society of Edinburgh. [Sess. 
and naked for about a day, then “ wool ” was again secreted. The second 
moult took place during the last week in April ; the buds of spruce began 
to burst about this date. The larva moulted for the last time during the 
first week in May. The adult fundatrices differed as follows : — 
A. Green laying green eggs. 
B. Yellowish-green laying yellowish-green eggs. 
The latter group were much the more numerous on the experimental area. 
By mid-May the effects of the feeding of the fundatrices became evident. 
The bases of the needles near the fundatrices became swollen, and such 
needles remained stunted. Five to ten days later, numerous reddish 
papillae appeared on the swollen parts. 
Generation II. Gallicola . — The first-stage larvae began to hatch out 
during the last week in May. They immediately crowded amongst the 
deformed needles. As a result of the feeding of these larvae further 
swelling of the needles took place, and a compact gall was formed by 
mid- June. Only the needles at the base of the shoot were affected; the 
shoot continued to grow, but was usually bent. Three moults took place 
within the gall at intervals of about two weeks. The galls began to 
open from 26th July. These opening first were derived from Group B 
fundatrices. The nymphs (fourth-stage larvae) climbed out of the gall on 
to the surrounding needles and moulted, becoming winged gallicolae. These 
were dealt with as described under “Technique,” I, 4. The majority of 
the gallicolae, transferred to or allowed to remain on spruce, settled and 
began egg-laying in twenty-four hours. The eggs were bright yellow, and 
numbered twenty to fifty. No “ wool ” was secreted by the gallicolae. 
Those gallicolae transferred to larch and, allowed freedom, climbed to the 
top of the needles and flew away. When the twigs were sleeved a few 
settled down and laid bright yellow eggs. In twenty to twenty-two days 
the eggs on spruce had hatched, giving yellow fundatrices ; by that time 
all the yellow eggs laid on larch had shrivelled up without hatching, or the 
larvae hatching from these eggs had died. Galls of this type continued to 
open until 10th September. The above experiments were repeated many 
times, and all gave the same results. 
Only two galls, derived from green fundatrices (Group A), were obtained. 
These galls opened on 1st and 3rd August. The gallicolae were slightly 
more green in colour than those of Group B. They were dealt with as 
before. No result was obtained from those remaining on or transferred 
to spruce. Those transferred to larch needles settled down, and laid twenty 
to thirty dark-green eggs under the protection of the wings of the mother. 
