55 



Out of 18 sprouts showing two lesions, 13 had the younger 

 lesion above and 5 the older, which might indicate the probable 

 work of insects in carrying infection. 



Sprouts were originally infected at the base in more than four- 

 fifths of the cases. Forty per cent, of the oldest lesions on 

 sprouts showed twigs as a centre of infection ; eighteen per cent, 

 showed cracks, fourteen per cent, wounds; thirteen per cent. 

 beetle holes, eleven per cent, crotches, and four per cent, were in- 

 determinate. 



More infections were found in medium dense growth than in 

 dense 1 growth, and very few in rather open growth. Of all in- 

 fections recorded, 17.3 per cent, were within twenty feet of old 

 logging roads, 7.4 per cent, from 20 to 50 feet away, and 45.3 

 per cent, at greater distance. Many more infections were found 

 where soil conditions were moderately moist than where they 

 were dry. Of 150 original sprout infections, 62, or 41 per cent, 

 had a north to northeast exposure; 20 or 13 per cent, a south to 

 smith west exposure; and the remainder were about equally 

 divided between the other two quadrants of the compass. This 

 might suggest moisture again as an important factor. 



There were 28 cases of pycnidia observed developing on wood. 

 Only eight trees larger than seven inches in diameter showed in- 

 fection. One of these had a lesion apparently two years old; and 

 half had the oldest lesion less than one year old. All of the tree 

 infection was in the bark of the trunk, none in the tops. Half 

 had development of watersprouts in connection with the lesions. 

 Lesions in the bark of stumps showed fissures at their centres 

 in almost all cases, and in the oldest ones the pustules were 

 usually dark and in the ascus stage. 



In connection with lesions on sprouts, trees, and stumps, there 

 were abundant evidences of animal association, principally 

 beetle and other large insect larvae, tunnels and holes; but also 

 woodpecker holes and claw marks, and ant nests and trails. 

 Most of the ant ne.sts were in old dried stump stubs. Fully nine- 

 tenths of all old lesions showed beetle larvae in or near them. 

 These were mainly a species of Leptura. Of the youngest lesions, 

 about two-fifths showed larvae in or near them; and in all cases 



