350 Proceedings of Royal Society of Edinburgh. [sess. 
some of the beetles feeding on the plant, showing that for some 
of them at least hibernation was over. This pine, which was alive 
but not flourishing, was watered at intervals. On 21st June 1897 
the living piniphilus were removed to fresh material. In the 
month of September the first beetles of the new brood issued, the 
flight holes being in the upper thinnest part of the main stem. 
On 1st October another piniphilus issued, and still another on 20th 
October. On 29th December 1897 dissection revealed a number 
of beds containing full-fed larvae. The theory of the two-yearly 
generation is thus disproved. 
As Pine 2 had never been very healthy, at intervals from April 
onwards I had placed in beside it cut lengths of Pinus sylvestris , 
paraffined at the cut ends so as to give the piniphilus a choice of 
other and thicker breeding material. 
The record from these pine logs is : — 
Log. 
Description. 
How long beside 
Living Piniphilus. 
Proof of Egg-laying. 
A 
20 inches long 
and 3 inches in 
diameter 
April 2 
to 
May 5, 1897 
On December 29, 1897, on strip- 
ping the bark from the log, 
fifteen larvse were got. Seven 
of them lay in beds deep in 
the wood, three in beds less 
deep, and two seemed only 
to have begun to gnaw out 
their bed. The remaining 
two larvse were smaller, and 
had not reached the full-fed 
condition. 
B 
24^ inches long 
and inches 
in diameter 
May 5 
to 
June 5, 1897 
Dissected on December29, 1897, 
and a larva found in its bed. 
In July 1898 a mature beetle 
issued. 
C 
26J inches long 
and 1^ inches 
in diameter 
June 5 
to 
July 13, 1897 
Dissected on December 29, 1897, 
when twelve beds were found, 
each containing a full-grown 
larva. These were covered 
over again. On July 16, 1898 
(not having been examined 
for more than a week), on 
opening the sack nine live 
piniphilus were got, their 
flight holes easy to see. By 
July 25 other five had issued. 
A tabular record of the successive pines used in the piniphilus 
