Page:Popular Science Monthly Volume 29.djvu/455

 of lumber and timber in long voyages are often badly injured by the growing mycelia between the pieces.

In bridges, ends of posts and struts, tenons and mortises, there are often similar growths of mycelia arising from the germination of spores by moisture, and decay eventually takes place. The illustration presented in Fig. 5 is one quite familiar to all who handle lumber and timber, but its import is not as generally understood as it should be, from the fact that such growths are thought to be due to the decay of the wood, instead of being the inducing cause.

A little more care in piling and stacking green lumber by producers and consumers, permitting circulation of air between each piece, would prevent the growth of various mycelia, and save annually large quantities of lumber.

If moisture collects and remains on seasoned timber, the mycelia will also grow and destroy it. Large timber should be seasoned under sheds, otherwise the sun will season an outside layer, preventing the escape of moisture, and internal growths of ferments and mycelia-fungi will destroy the inside of the timber, a thin outer shell remaining sound for some time.

The illustration is one of the most important that can be presented. It shows the destruction induced by the growing mycelium on the wood. On the right and lower edges, where the growth first appeared, it has caused the wood to crack not only with the fibers, but across, and in a short time longer it would have fallen to pieces, as portions of adjacent planks had some time previously. The form of fructification of the fungus of mycelium shown in Fig. 5, as found, was resupinate, attached to the under side of the plank as that shown in Fig. 6, which is a species of Polyporous very destructive to hemlock in inclosed warm and damp places.

Resupinate forms of the Polyporei are very common on the under side of boards and timbers they are destroying, covering irregular areas; some will be ten by four inches, others follow along the edge of a board adjacent to a wall, ten to twenty inches, having an irregular width of one to two inches, the pores always pointing downward. A definite contour not being followed, identification of the species is often very difficult.

Fig. 7 shows the under and upper sides of the fruit of the fungus Lentinus lepideus (Fr.)—"Scaly Lentinus"—an agaric, and in this immediate territory is the one so destructive to timber of yellow or Georgia pine (Pinus palustris, Mill) in bridges, docks, and railroad-ties.

I have also found it upon the timber of Pinus mitis. Being the first