Chermes Laricis. 19 



It must not be implied from the foregoing 

 remarks that this disease is found only in 

 neglected, over-crowded, and ill-chosen plan- 

 tations ; it is found in healthy and carefully 

 thinned plantations, and where the soil and 

 site are in every respect suitable to the tree, 

 and I have myself verified this ; but in a case 

 of this sort, there is no blame — no action on 

 the part of the forester could have prevented 

 it, no foresight could have controlled it. In 

 such instances, the trees may after a while 

 recover, though the timber in after years may 

 be somewhat faulty and defective. 



It is somewhat strange, but in more than one 



instance when I have been microscopically 



investigating the canker, and examining the 



fungus, I have found evident traces of an attack 



of the Chermes laricis, larch bug, or aphis. 



The evidence has been in the discovery of the 



eggs on their hair-like stalk situated at the 



base of the leaf-knots. In these cases the 



whole of the upper portion o^ the young trees 



have been dead, as if the vital fluid had been 



sucked away by the host of aphidae which 



attacked them. The attack may continue 

 C 2 



