1900 ] BRIEFER ARTICLES 49 
upon the larger ones. It appears first in the fall, soon after the 
autumn rains begin, as small, irregular, brown, sometimes slightly 
depressed, areas of the bark. During the fall and winter months it 
spreads but slowly, but with the advent of warmer weather in spring, 
growth takes place rapidly until the disease has invaded an area sev- 
Fie; 1; Fic; 3: 
eral inches in diameter. Such areas under observation at Corvallis, 
Oregon, the past season cease to enlarge late in May, and early in June 
the first evidence of spore formation was seen. At that time the dis- 
eased areas were dark brown in color, markedly depressed, and in 
most instances limited by ragged, irregular fissures which separated 
the dead from the surrounding living tissues (figs. 7, 2). These dead 
Spots vary in size from those not more than one half inch in diameter 
to extensive areas two or three inches wide by six or eight inches long. 
Occasionally a single area completely girdles a branch, thus killing at 
Once its distal portion ; but nore commonly only a dead spot occurs, 
Mo. Bot. Garden, 
{90I. 
