188C).] NEW YORK ACADEMY OF SCIENCES. 119 



may canse active chemical action wlicn tlie ducts are first 

 opened. 



Mu. Dudley, in answer to Mr. Collingwood, said that micro- 

 scopic examination of different woods showed more in relation to 

 the strength than the durability, though it would determine 

 whether the stored products in the medullary rays were in the 

 form of starch, the most stable form, or in sugar, glucose, etc. 

 Tlie catalpa, by its structure, does not indicate the great dura- 

 bility ascribed to it. Woods which have lai-ge bundles of medul- 

 lary rays filled with compounds are more easily induced to decay, 

 as a rule, tlian those which have smaller bundles. The micro- 

 scojiieal examination would show at once whether incipient 

 decay had commenced. In cutting timber and preparing it for 

 use, it was impossible to prevent the access of numerous spores 

 of various fungi in the air, and when proper conditions were 

 present, they would germinate. 



Thoroughly seasoned wood could be painted with advantage, 

 otherwise it was an injury, because it held the moistened spores 

 in the wood, and decay would take place. 



Mr. \V. Barclay Parsons gave illustrations from his expe- 

 rience of the variation in the durability of timbers and bridges 

 under like conditions, and discussed ihe matter of painting and 

 covering bridges. In one old bridge, the oak posts were sound, 

 but the ]iine chords were gone. 



Mr. Dudley said it was economical to paint bridges when the 

 timbers were small and well-seasoned; but the joints and ends of 

 the timber must be well protected. Timber should be seasoned 

 under cover, and not in the sun. He thought bridges were bet- 

 ter covered than jiainted. 



Dr. Schoeney discussed the subject of fungi attacking wood, 

 as being analogous to human diseases, and its bearing upon the 

 germ theory. In answer to his question, Mr. Dudley^ said he 

 thought the mycelium could penetrate the epidermis and corky 

 layer of living trees if moisture could soften them. 



Dr. Britton briefiy described the life history of these higher 

 fungi. 



President Newberry commended the paper, and spoke of 

 the importance of the study. He had in his museum specimens 



