or liie cycles in the year, I have said Lhat the insect lays about 
2° eggs and therefore one female beetle may produce in the year a 
progeny of 200,000, on the supposition that only five generations 
are passed through and that only half the eggs are females (the 
latter however, are usually in excess of males), ff there is a 6th 
generation the number of females incre ses to 2,000,0 00. 
Taking only 50 per cent of the 5th generation beetles as matur- 
» ing and laying eggs, we still have 100,000 insects as the progeny 
of the one mother beetle in the spring. This great prolificness 
easily explains why bamboos suffer so greatly from the shot-borers 
attacks. 
Towards the end of April of this year Mr. Williams, the Superin- 
tendent of the Telegraph Workshop, at Calcutta, informed me that 
bamboos which he was converting into field telegraph posts for use 
in frontier expeditions and elsewhere were being attacked and 
riddled by insects. The specimens he sent me f identified as the 
common bamboo boring insect (. Dinodermits mhmtxs , Lesne). As 
the question of the preservation of bamboos against this insect had 
been engaging my attention for some time, 1 immediately paid a 
visit to the workshops and examined the bamboos. I found that 
they were being' experimentally treated in the following manner 
before being fitted up as telegraph posts : — 
(1) Five days soaking in river water: 
(2) Five days soaking in a solution of copper sulphate, after 
which they were dried in a covered shed for several days; 
and then 
(3) Soaked for 24 hours in common Rangoon oil. This latter 
has the effect of darkening the bamboos and the smell of 
the oil remains in them for some considerable time, al- 
though not so offensively as to prevent their being made 
use of. The treatment lasted about 14 days upon the ex- 
piration of which period the bamboos were at once sent 
to the workshop to be fitted. Mr. WILLIAMS bad reported 
that within three week% of this treatment some of the 
bamboos bad been again attacked by the borers. As some 
9,000 had been through the treatment the case afforded a 
good opportunity for experiment. I wished to find out 
(1) How many more generations of the beetle appeared in the 
year. 
(2) Whether the oil treatment was of any use. 
(The experiments, which numbered fifty-five, took place between 
April 29th and October 30th. Male bamboos i. e. solid bamboos 
were placed in boxes constructed of tin- foil with close fitting tops 
of wire gauze and treated in various ways with water, copper 
sulplate and Rangoon oil both singly and in combination.) 
The experiments show I think the following : — 
(1) That neither the five days in water nor that followed by a 
