62 
structure, and until it is so badly damaged that it must be replaced 
by new material. 
When we take into consideration the enormous amount of timber 
used in railroad construction alone, and the damage to such material 
by insects, from the time it is taken from the forest until it is replaced 
by new material in the structure, it is plain that we have in this an 
economic problem worthy of special attention. It involves not only 
the determination of methods of preventing losses to vast commercial 
interests, but the conservation of our forest resources, and the economy 
of present and future supplies of that which is in greatest demand. 
When there was an abundant supply of timber it was possible to 
select only the best and to discard the defective, but at present it has 
become necessary, on account of the growing scarcity, to use much 
timber that is defective. This is evident from the character of the 
railroad ties and other construction material observed in the lumber 
yards, and piled along the road ready for use. Therefore, the prob- 
lem of treating defective timber to promote its durability is becoming 
an important one. The need of investigations to determine the true 
character of the various kinds of defects caused by insects and their 
relations to the entrance of wood-decaying fungi, as a preliminary to 
the discovery and adoption of practical methods of checking or pre- 
venting premature decay, is apparent. 
In the accumulation of data relating to the kinds of insects to blame 
for the commoner injuries, and to some important features in their 
habits, life history, and distribution, considerable progress has been 
made within recent years. While this technical knowledge of the 
insects, the characteristies of their habits, and the character of their 
work is of prime importance in suggesting methods of preventing 
losses, there is a feature relating to experiments with such methods 
to determine and demonstrate their practical application, which 
requires a considerably greater expenditure of money and time than has 
yet been available. Indeed, the funds available from public appro- 
priations for original investigations of this character are not sufficient 
to warrant the undertaking of the elaborate experiments necessary. 
If, however, private individuals, or companies whose immediate inter- 
ests are involved, would cooperate with departments of scientific 
research in this work, as is being done in some other lines of investiga- 
tion relating to forestry problems, it is believed that results of the 
greatest value could be attained. 
Mr. Cockerell asked whether a moderate number of forest pests 
might not in a way be beneficial by killing out the old trees and leay- 
ing room for the young ones to grow. He also mentioned the curious 
habits of the sugar cane Xyleborus in the West Indies, which, from 
attacking dead wood, had come to attack the living sugar cane. 
