ae) Oe. Se 

SIREX GIGAS, LINN., IN BUTE AND ARRAN. 189 
I had these pieces of wood under observation all summer, and 
at the beginning of August the first flies made their appearance 
from the wood, through circular openings slightly smaller than 
the ordinary holes bored in the larval stage. 
How long the eggs take to hatch and the insect remains in the 
larval state I have still to learn. But now that it is known to be 
a native of some of our woods in the Clydesdale district, data may 
soon be forthcoming to clear up those points. The places to look 
for it are where Scotch and Silver Firs grow in some abundance. 
I am convinced that if more of our woods in other localities were 
properly examined the fly would be found in them too. 
Trees which have begun to decay should receive careful atten- 
tion, as the fly seems to attack them in preference to those which 
are healthy and growing. The tree from which these pieces 
containing the larvee were taken was partially dead when it was 
cut down, But whether the eggs had been deposited while it was 
still standing, or not until it had been cut down, it is difficult to 
determine. The larve do not seem to be able to continue their 
operations after they have been disturbed or exposed in their 
borings, but soon shrivel up and die. At least this has been my 
experience with them, and it prevents observation of their opera- 
tions, which would, no doubt, prove interesting and instructive. 
