DISEASES OF TAXODIUM AND LIBOCEDRUS. 



peckiness in the latter extended upward into two main 

 branches for 20 ft. At the points where all recognizable 

 traces of the disease ceased, the branches had about 150 

 annual rings. A third tree was sound for 60 ft. from the 

 base, then became very pecky, the peckiness passing up 

 into two or three main branches, and still another was pecky 

 3 ft. from the base and upward. The extent of peckiness 

 varies, i. e., in one trunk the holes may be several inches 

 apart, or scattered all over the cross-section, in another they 

 may be confined to the first 150 rings. Nowhere was a 

 single tree seen hollow, at least none which was hollow be- 

 cause of an advanced stage of peckiness. In this respect 

 this disease affects the cypress just as Trametes Pini does 

 the pines. One never finds a pine hollow because of 

 disintegration caused by Trametes Pini. This is especially 

 to be noted, as it will be referred to again. It is a notice- 

 able fact that in traveling through cypress forests one 

 rarely sees many fallen trees, and where violent wind- 

 storms have overthrown any number of trees, these are just 

 as often trees sound at the base as those which are diseased. 

 In the fall the whole tree falls, i. e., the trunk does not 

 break, as do many pines and deciduous trees, in which the 

 entire heartwood may have been destroyed, by such a para- 

 site as Polyporus sulphureus. The oldest trees e. g., in 

 which about 1800 rings were counted (southern Louisiana), 

 have the same appearance as those but 200-300 years in age. 



STRUCTURE OF DISEASED WOOD. 



The wood of Taxodium is composed of tracheids with 

 one or two rows of pits. The growth rings are rather broad, 

 the summer wood about one-third the width of the spring 

 wood. Kesin passages are wholly wanting, and in their 

 stead there are numerous resin cells either scattering or in 

 tangential bands.* The amount of resin in the wood is 



* Penhallow, D. P. The generic characters of the N. A. Taxaceae and 

 Coniferae. (Trans. Roy. Soc. Canada ii. 2 : 51. 1896.) 



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