1886.] NEW YORK ACADEMY OF SCIENCES. 115 



put down and completely covered by sand and ])aving, in the 

 Grand Central Station, in 1871. It was taken out last month. 

 The strength of the wood is destroyed, and it will crumble on 

 further drying. I found several budding cells of ferment simi- 

 lar to the yeast plant in appearance, and a few cells of the genus 

 Protoooccus, and an abundance of dark liypiise, which give color 

 to the wood in streaks. In what were checks in the wood when 

 l)ut down, are the remains of perithecia of some of the Spliceria. 

 Tlie action here was very slow but sure; the outer lamella of 

 each cell being destroyed more than the otliers. By wetting and 

 careful manipulation, they can be separated, showing their form 

 more perfectly than those obtained by the ordinary mnceration. 

 Some of the hiphwria grow under the bark of live trees, some- 

 times killing them, and are ready, as soon as vital functions of 

 the tree cease, to pierce their host with tiie abundant hyphse, 

 and carry on their woi-k of destruction. 



I find on unpainted telegraph poles* many places where the 

 growing perithecia have burst and broken one to two layers of the 

 wood-cells; and this is repeated as fast as the projjer conditions 

 ensue, thus aiding in the mechanical destruction of the tissue. 

 JSTear the ground line, other fungi send out mycelia which follow 

 down the cells of the wood rapidly, but piei'ce the wood trans- 

 versely in a slower manner. As the mycelia get farther away 

 from the air supply, the fermentative action becomes more 

 marked. I mention these points for the reason that, when ex- 

 amined separately, it is hard to understand their connection; 

 and it is the Consideration of these two extreme conditions which 

 has led to part of the controversy regarding the relation of fungi 

 to decaying wood. There is less real distinction between the so- 

 called "dry rot" and wet rot than is usually supposed, as both 

 must have moisture, a suitable temperature, and some air to 

 induce decay. Though the final result is the same in all cases, 

 it does not 03cur in the same way in all kinds of wood. 



The subject must be treated specifically, and not in the gen- 

 eral manner adopted by writers. Each species of tree has 

 special fungi, as it has insects, which are not found to any ex- 

 tent upon other kinds of wood. Red cedar, cypress, yellow 

 pine, are not affected, as a rule, by the same fungi which quickly 

 destroy the sycamore, maple, hickory, and bass wood. 



The structure of all these woods, their stored products, and 

 the intercalated substances in their cellulose walls, differ from 

 one another, as do each of our extensive flora of over four hun- 

 dred species, and they are distinguishable under the microscope 

 by a difference of cell structure, arrangement, and chemical 

 products as readily as the botanist recognizes them by exterior 

 growth of form, leaves, flowers, or fruit. 



