358 Proceedings of the Royal Society of Edinburgh. [Sess. 
first-stage larva of the Fundatrix bear one central, double-contoured wax- 
pore. The secondary vein of the hind wing of the winged forms leaves 
the longitudinal vein at an acute angle. 
2. Nomenclature of the Generations. 
The main features of the various generations are as follows : — 
I. The first-stage larva hatches in autumn, and is the hibernating 
stage on spruce. Development is completed in spring. This 
generation is apterous in all stages. Its feeding habits begin 
the hypertrophy which results in the formation of the gall. 
This generation is parthenogenetic, and each female lays a 
very large number of eggs. 
II. Stages 1 to 4 of this generation are passed within the chambers 
of the gall. This gall is formed by the coalescence of the 
spruce needles. When the fourth or nymph stage has com- 
pleted its development the gall opens, and the final moult 
gives the winged adult. This winged adult (a) may remain 
on spruce, giving rise to Generation I, or ( b ) may migrate to 
the non-Picea host. The females of this generation are not 
so prolific as those of Generation I. 
III. The first-stage larva of this generation is the hibernating stage 
on the intermediate or non-Picea host, except in the genus 
Pineus, where the hibernating insect is a third- or fourth-stage 
larva. This generation resembles I, but the females generally 
lay fewer eggs. The parthenogenetic adult may give rise to 
two kinds of larvae — (a) larvae which remain undeveloped for 
a period of time, ( b ) larvae which develop into apterous 
parthenogenetic adults. There may be a series of the latter 
group. 
IV. This generation arises from Group III (b). It gives a generation 
which is winged in the adult stage. It resembles Genera- 
tion II, but development does not take place within a gall. 
The adults migrate to spruce, and there lay a small number 
of eggs. 
V. This is the sexual generation, which is apterous in all stages. The 
female lays but one egg, which begins the cycle again. 
The following is a table showing the names given to these generations 
by the various authors : — 
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