7G6 EXPERIMENT STATION RECORD. 



virginiana and J. harhadensis. Hitherto but few diseases of the red 

 cedar have been described, the most important being the so-called cedar 

 apples, due to a species of Gvmnosporangium, 



The m3'celia of 2 fungi were observed growing in the heartwood of 

 manv trees and bringing about characteristic changes which rendered 

 the wood unfit for lumber. A study conducted in central Tennessee 

 and southern Missouri showed that these 2 forms of decay were present 

 in each region. The most striking form is one called white rot of the 

 red cedar, due to P(Ay por us juniper Inua. It causes long holes in the 

 heartwood, which often unite, making tubes through the entire trunk. 

 At first the holes are separated h\ long stretches of wood which is 

 apparenth' unchanged, but closer examination shows this wood is of a 

 reddish-brown color instead of the deep red of sound wood. The 

 holes are lined with a brilliant white coating, which consists of almost 

 pure cellulose of the original wood, the incrusting lignin substances 

 having been removed. In the larger holes the amount of wood fiber 

 which has been reduced to cellulose is very considerable. In the older 

 holes the white lining is almost absent, the walls at this time being 

 covered with a felt of soft brown mycelium. 



The changes which the fungus causes in the wood are described at 

 considerable length. The fungus apparenth' enters the trunk through 

 a dead branch and when the hj^phse reach the heartwood they grow 

 both upward and downward. This disease is seldom noticed in trees 

 25 years old, but is most abundant in those considerably older. A 

 study of the fruiting body of the fungus has shown that it is a new 

 species, and a description is given of it. 



The second disease is described as that called red rot, or peck}- cedar. 

 This is perhaps more common than white rot and has been observed in 

 cedar trees over a considerable portion of eastern United States and 

 also in specimens received from Bermuda, and has also been observed 

 on arbor vitaj in Maine, where it produces the characteristic brown 

 pockets. Wood affected with this disease is full of these spots. In 

 the early stages these are free from one another and are more or less 

 filled with a brown metamorphosed wood substance, which is cracked 

 so as to form small cubes adhering to the walls of the pockets. The 

 pockets are of different sizes, varying in length from 1 in. to several 

 feet. In cross section the}^ are nearly circidar when small l)ut become 

 irregular when old, and frequentl}- a number join together, making 

 large irregular holes full of brown wood which has the appearance and 

 properties of brown charcoal. The line of demarcation between the 

 brown wood and the normal heartwood is ver}^ sharp. 



The structural changes caused by this fungus are described, as well 

 as the nwcelium and fruiting body. Although mature spores have not 

 been found, on account of its flesh-colored hymenium it was regarded 

 as a form of Poly par us came us. 



