8 



of the observations are also incomplete. Owing to the large area over 

 which the trees grow, the conditions are very varied. Moreover, 

 the opportunities for obtaining material are restricted to localities 

 where the timber is cut for commercial purposes, and these localities 

 and the manner in which the trees are cut are often unfavorable to 

 research. 



The writer is under obligations to Mr. W. B. Earthman, of ]Mur- 

 freesboro, Tenn., and Mr. Fred Heim, of St. Louis, for courtesies 

 which the}' extended to him while pursuing his studies in their locali- 

 ties, and also to Dr. W. G. Farlow and Prof. L. M. Underwood for 

 their courtesy- in allowing him to examine their herbaria of Polypori. 



WOOD OF THE RED CEDAR. 



The wood of red cedar is rather light and soft and its tensile strength 

 is not great. The heartwood is a deep red; the sap wood is very narrow 

 and very white, contrasting markedly with the dark heartwood: the 

 annual rings are very narrow, owing to the slow growth of the tree 

 (the trunk shown in PI. Ill has 65 rings, of which 16 belong to the sap- 

 wood). There are no resin ducts, as in the wood of the pine, but 

 numerous isolated resin cells are scattered throughout the annual rings, 

 and in the heartwood these are generally filled with a hardened resin. 



GENERAL REMARKS ON THE DISEASES OF THE RED CEDAR. 



Comparatively few diseases of the red cedar have heretofore been 

 described. The most important fungi attacking this tree cause the 

 so-called cedar apples, these being due to species of Gymnosporangium. 

 The mycelia of these fungi flourish in the wood of the youngest 

 branches and stimulate the cambial cells, causing them to grow very 

 rapidly and form swellings or tumors,^ and in one case they have 

 been known to cause a witches' ])room. The influence of these fungi 

 on their host is not marked. They deform a few branches, but unless 

 very plentiful do but little damage. 



The m3^celia of two fungi grow in the heartwood of many of these 

 trees and bring about characteristic changes which render the wood 

 unfit for lumber. In some cases entire car loads of cedar posts shipped 

 from Tennessee and Missouri have been found to be so badly rotted 

 by one or the other of these forms as to be of little value. One dealer 

 in cedar lumber estimates that at least 60 per cent of the trees in his 

 locality are defective owing to these fungi. A careful study of the 

 trees in the neighborhood of Murfreesl)oro, in central Tennessee, and 

 also of those in southern Missouri showed that both forms of decay 

 were present in each region. Very few insects bore into the heart- 



'Wornle, Paul, Anatomische Untersuchung der durch Gymuosporangiuiu-Arten 

 hervorgerufeneu missbildungen (For!?t. Naturwiss. Zeitsch.. 189-4, Vol. Ill, p. 68). 



