Graves : Diseases of Trees in New York 1 1 5 



base of the trunk, being about lYz feet in diameter. Often, how- 

 ever, trees are eventually killed out, especially if due to suppres- 

 sion their diameter growth is slow. 



The fruiting bodies, or perithecia, begin to ripen in August ; 

 and although some were found to contain mature spores by the 

 end of the month, in most cases the spores are not ripe until the 

 latter part of September or in October. During the winter it is 

 possible to obtain ripe fruiting bodies on almost any canker. 

 Sometimes these are few and very inconspicuous, being scattered 

 about singly or in twos or threes in crevices in the bark ; but 

 occasionally their aggregation in groups makes them readily 

 visible. But even where very few, they can be easily detected 

 with the naked eye (being a Httle less than .5 mm. in diameter) 

 appearing' as small, bright crimson dots, located on the diseased 

 bark, not far from the border line of healthy and diseased tissue. 

 In shape the perithecia are ovoid: 19 specimens taken from dif- 

 ferent sources measured 406 X 288 /x. 



The ascospores are colorless, two-celled, and when ripe, often 

 show pronounced constriction at the septum. The majority of 

 the specimens examined were very blunt or rounded at the ends 

 when mature, although many were fusoid, and in the younger 

 stages they were always fairly sharp pointed. Measurements of 

 75 spores from various sources, averaged 14.5 X 7-5 These 

 figures agree with those given in the North American Flora,^ 

 except that our spores are a little wider. But Dr. Seaver, to 

 whom specimens were submitted, says that there is no doubt that 

 it is Creonectria coccinea (Pers.) Seaver. 



Macroconidia developing from pure cultures on oat agar were 

 yellow in mass, transparent when viewed under the microscope, 

 averaging about 70 X 6 /x, blunt at the ends and with 5 to 8 septa 

 — usually 7. They are slightly curved, and usually a trifle thicker 

 toward one end (Plate 10, fiig. 4, a). 



Of exsiccati, N. A. F. 161, Nectria coccinea Fr. collected at 

 Newfield, N. J., on bark of dead Magnolia, showed spores aver- 

 aging about 16 X 5 fi, without constrictions. Fungi Col. 2043, 

 Nectria CO ccineaFr., on Tilia americ ana, 'London, Canada, showed 



5 Seaver, F. J. Hypocreales, in North American Flora 31 : 21. 1910. 



