HEALr>-WoLF: Whitening of the Mountain Cedar 207 



white patches are so commonly found on the mountain cedar that 

 Bray"^ used this character as one of the pecuharities by which 

 to identify the tree (fig. i). Upon these whitened areas may 

 be found stromatic nodules containing the fruits of the fungus. 

 On the older affected parts the branches become decorticated and 

 the wood corroded so that dark, very prominently projecting 

 wood nodules remain (fig. 2). On large trunks or branches of 

 on parts not diseased for so long a time, the grayish nodules are 

 embedded in the tissue of the bark and project only slightly or 

 quite prominently (fig. 5). These nodules occur singly, or quite 

 frequently two (rarely three) have fused end to end or partially 

 along one side. They vary in length from less than i mm. to 

 2.25 mm. and are more or less lenticular in form. Those on the 

 wood (pi. J I, f.i) are more frequently longer and not so wide as 

 those on the bark (pi. ji, /. 2), the latter being more nearly 

 oval. 



Projecting from the nodules are one to three short papillae, 

 marking the ostioles of the embedded perithecia. The ostioles 

 are rarely in the center of the nodule but typically nearer one end 

 (pi. ji, /. I, 2). The perithecia are prostrate, the neck of the 

 perithecium being bent upward toward the surface (pi. ji, 

 f. 5, 4). They are flask-shaped, with a slightly tapering 

 neck, and vary in size from 825-1200 X 260-400/x. By the cor- 

 rosion of the tissue of the nodule, an elongated cavity is formed, 

 the cavity-wall serving as the perithecial wall and being lined 

 with only a delicate fungous membrane. 



The numerous cylindrical asci, each containing six or eight 

 filamentous spores, are embedded in a mucilaginous substance. 

 When the nodules are moistened, the swelling of this mucilagi- 

 nous matrix causes the extrusion of the asci and spores (pi. ji,. 

 /. 4) from the ostiole. The asci vary in size from 800-1100 X 

 8-iO/A and have a very characteristically thickened apical wall, 

 which compels the rupture of the lateral walls toward the base of 

 the ascus. The spores which project from the broken basal end 

 (pi. ^i, f. 5) are always more or less coiled or twisted in response 

 to the presence of moisture. The spores are very long, ranging 



* Bray, W. L. Forest Resources of Texas ; Bull. U. S. D. A. Bureau of 

 Forestry 47: 54. 1904. 



