THE 



POPULAR SCIENCE 

 MONTHLY. 



AUGUST, 1886. 



WOODS AND THEIR DESTRUCTIVE FUNGI. 



By P. H. DUDLEY, C. E. 

 I. 



IN the forests which have contributed so much to the industries and 

 wealth of the United States there are seventy species of trees 

 which have been and are of great commercial importance, and three 

 hundred and forty more species which have an economic value. But 

 few countries have so great a variety. 



A section from the trunk of a tree of nearly the entire list of the 

 species, gathered from all parts of the United States, can now be seen 

 in the great and valuable collection in the American Museum of Nat- 

 ural History of New York City, contributed by Mr. Morris K. Jesup. 

 The difficulties attending such a great work, so as to show the appear- 

 ance of the wood and size of the tree with its bark, can only be fully 

 appreciated by those actually engaged in making the collection. The 

 magnitude of the work is without precedent ; and, while it has been 

 possible to transport across the continent a section of a tree, it has not 

 been possible to fully protect some of them from the attacks of fungi, 

 and some species will have to be replaced, while others by seasoning 

 have checked the ravages of their fungi, but they show discoloration 

 of the wood. To many this is an objection, but, by showing what 

 species easily decay, it enhances the economic value of the collection. 

 So many of our primitive forests have been cut, that many species for 

 general use are already consumed, and the importance of these speci- 

 mens for study, in making selections for substitutes, can not be over- 

 estimated. 



An inspection of the different species shows the marked diversity 

 in the structure and appearance of the woods, and one is quickly re- 

 lieved of the general impression that they are all alike. Examined 

 microscopically, the differences in structure are sufficient for identifi- 

 vol. xxix. 28 



