nd sections show that they are in strata
corresponding to the years' growth. =Polyporus igniarius= (L.) Fr.
[_Fomes igniarius_ (L.) Fr.] is a black species, more or less
triangular, or sometimes hoof-shaped. The yearly zones are smaller,
become much cracked, and the tubes are dark brown. One of these plants
which I found on a birch tree in the Adirondacks was over 80 years old.

The genus _Merulius_ has a fruiting surface of irregular folds or
wrinkles, forming shallow, irregular pits instead of a deeply
honey-combed surface. =Merulius lacrymans= (Jacq.) Fr., the "weeping"
merulius, or "house fungus," often occurs in damp cellars, buildings,
conduit pipes, etc. It is very destructive to buildings in certain parts
of Europe (see Figs. 189, 190). =Merulius tremellosus= Schrad., is very
common in woods during autumn. It is of a gelatinous consistency, and
spread on the under surface of limbs or forms irregular shelves from the
side (see Figs. 191, 192).

[Illustration: PLATE 73.--Merulius lacrymans. FIGURE 189.--Upper plant
in conduit pipe leading from wash room, Gymnasium C. U., Autumn, 1899.
FIGURE 190.--Lower plant from under surface decaying hemlock spruce log
in woods near Freeville, N. Y., October, 1899. Margin of plants white,
fruiting surface a network of irregular folds, golden brown, or brown.
Copyright.]

[Illustration: PLATE 74.--Merulius tremellosus. FIGURE 191.--Natural
size.]

[Illustration: FIGURE 192.--Enlarged to show character of fruiting
surface. Fruiting surface yellowish; margin and upper surface in
shelving forms, white, hairy. Copyright.]

[Illustration: PLATE 75, FIGURE 193.--Phlebia merismoides. On rotting
log, woods near Ithaca, November 23, 1898 (No. 2634 C. U. herbarium).
Various shades of orange, yellow or yellow brown when old. Copyright.]

[Illustration: PLATE 76, FIGURE 194.--Phlebia merismoides. Portion of a
plant 2-1/2 times natural size, to show interrupted folds of fruiting
surface. For colors see Fig. 193. Copyright.]

CHAPTER X.

HEDGEHOG FUNGI: HYDNACEAE.

The plants belonging to this family vary greatly in size, form, and
consistency. Some of them are very large, some quite small, some are
fleshy in consistency, some are woody, corky; some membranaceous; and if
we include plants formerly classed here, some are gelatinous, though
there is a tendency in recent years on the part of some to place the
gelatinous ones among the trembling fungi. The special character whi