154 Proceedings of the Royal Physical Society. 
recent pine and spruce clearings. Unfortunately it is a prevalent custom 
in Scottish forestry to plant felled areas immediately after the removal of 
the timber. As a result of this custom H. ater and H. cunicularius are 
encouraged. | | 
The methods of attack of H. ater and H. cunicularius are exactly similar, 
as are also the injuries they cause to the young plantations. The best 
example of an attack by the two species, which I have had an opportunity 
of observing, occurred on Darnhall Estate, Peeblesshire. It began in 1910 
on a narrow strip planted that year, known as the Laidlaw strip, and spread to 
an adjoining area felled during 1915-16, and planted in spring 1916. This 
area is known as the Kaim Wood. Both areas contain spruce and Scots 
pine stumps. I first observed the presence of Hylastes in the Laidlaw strip 
in October 1915, where I found numbers of A. ater and H. cunicularvus on 
the young plants. I made a rough estimate of the plants attacked during 
two subsequent visits in October and November, and concluded that about 
30 per cent. of them had been killed. The Pine Weevil, Hylobius, however, 
was also present in the area. 
The source of infection of this area by Hylastes lay, I believe, in the felled 
areas on Portmore Estate on the other side of the valley, where felling had 
been going on for some time. This much is certain, that neither of the 
species of Hylastes was breeding in the particular area under observation, 
as all the stumps which I examined in it were rotted with fungus and could 
afford no suitable habitation for Hylastes. At this time (October 1915), the 
Kaim Wood was only partly felled and harboured few Hylastes. Out of 
seven stumps examined only one yielded beetles. On it I found three 
adult H. ater and a few larve. In April 1916, I again visited the two 
areas, and again found H. ater and H. cunicularius on the young plants on the 
Laidlaw strip. The Kaim Wood, however, was covered with snow, and I 
made no attempt to examine the stumps in it. My next visit was delayed 
until August 1916, when I found the plants on the Laidlaw strip almost 
free of Hylastes. In the Kaim Wood, which was by this time felled 
and planted up, I found both H. ater and AH. cunicularius attacking the 
newly-planted conifers, and also breeding in the stumps and roots in large 
numbers. All stages of both species were present on the roots—egg, larval, 
pupal and adult. The Pine Weevil, Hylobius, was also present in the adult 
stage in the plants, and in the larval stage in the stumps and roots. I now 
had an opportunity to make a careful and systematic examination of all the 
sickly and dead plants (which amounted to nearly 60 per cent. of the total — 
number in the area), Mr Chalmers, Overseer of Darnhall Estate, having 
granted me permission to uproot such sickly plants as were unlikely to 
