l888.] NEW-YORK MICROSCOPICAL SOCIETY. 119 



caused by Lentinus lepideus, Fr., will be retarded ; though the 

 exposed ends of the ties will be more subject to the attacks of 

 Trametes pini, Fr. Nevertheless, the rate of decay, caused by 

 the last-named fungus, being slower, the service of the Yellow 

 Pine Ties is prolonged by the less depth of imbedding in the 

 ballast. 



" It must be understood, that the decay of ties of all species 

 of wood will not be retarded by less imbedding in the ballast. 

 On the contrary the decay of ties of some woods is retarded by 

 full imbedding. 



" In securing pieces of decayed Yellow Pine ties from the 

 main tracks of a railroad for microscopical study, it is rare to 

 find, in fruit, the fungus which has induced decay. The mycel- 

 ium, and its method of destruction only remain to indicate what 

 caused the decay. A slight difference in color was frequently 

 noted between the mycelium found in the lower, and that found 

 in the upper portion of the Yellow Pine ties ; but the cause was 

 not understood until, in the Fall of 1886, I found both species 

 of fungus, herein mentioned, fruiting upon the same Yellow Pine 

 track-stringer for the transfer-table, at the Grand Central Sta- 

 tion. Both species also fruited on the same stringer the present 

 season. Specimens of each fungus are in the boxes for exhibi- 

 tion. 



" Sphceria pilifera, Fr., often attacks new Yellow Pine ties in 

 transit from the South. The mycelium penetrates the resin- 

 ducts and cells of the medullary rays of the alburnum, the dark 

 filaments discoloring the portion of wood attacked. If such 

 wood dries, or is treated before putting it in the ground, the 

 decay, for the time being, is arrested. The final decay of the 

 wood may be due to a subsequent attack of another species of 

 fungus, the mycelium of each often being found in the same 

 wood-cell. This is especially true of decayed sheathing from 

 freight-cars. Much of it is attacked by fungi, discoloring the 

 wood, to some extent, before it is used on the cars. In many 

 cases painting such wood hastens, instead of preventing decay." 



Mr. Dudley also exhibited a Heliostat, of his own construction, 

 made after the model of the Fahrenheit Heliostat, and showed 

 the method of operating the same. 



In this connection Mr. Dudley also exhibited Daguerreotypes 



