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painting materials

The result of attacks of dry rot may be more or less severe and treatment of
the wood which has decayed will have to be carried out according to the require-
ments of particular cases. In all cases where wood has been attacked by fungi
some has been used for their nourishment and the structure is weakened. With
this weakening the wood becomes more red in color and more brittle, loses its
characteristic odor, gives a dull sound when struck, shrinks, and often warps. It
may or may not have visible fungus on the surface but in advanced cases will
show cross-shakes and cup-shakes—fractures running at right angles to the grain,
with, in the latter, a curling into concave flakes between the fractures.

name	surface growth *
Merulius	White to gray strings sometimes as thick
lacrymans	as a lead pencil; brittle when dry; auxil-
(domesticus)	iary growth in dense sheets with large
bracket-like and scalloped fruit-bodies.
Polyporus	White   strings   and   auxiliary   growths,
vaporarius	never colored, with fruit-bodies in thin
(group)	sheets, all white.
Coniophora	Slender strings becoming red-brown, and
puteana	fruit-bodies yellow to olive-brown, sheet-
(cerebella)	like and with minute pimples.
Paxillus pan-	Very slender, yellow to brownish yellow;
noides (Acker-	fruit-bodies shell or fan-shaped, surface
untius)	yellow to brown and with radiating gills.
Lemites sat-	No strings; occasional sheets or cushions,
piara and L.	tan in color; fruit-bodies from wood cracks
abietina	are yellow to umber with radiating gills.
Polyporus de-   No strings or other growths on surface;
structor	bracket-shaped fruit-bodies, white to gray.

comments
Little moisture needed; rot
runs through and causes
cross-shakes.
Members of this group need
more water than the Meru-
lius lacrymans.
Needs much moisture; rot
incomplete, often without
cross-shakes.
Takes much moisture; wood
when attacked first takes on
a characteristic yellow color.
Demands much moisture;
fungus remains inside and
resists death from desicca-
tion; external wood may re-
main intact except for cross-
shakes and cup-shakes.
Demands much moisture;
decay internal.

* Since, in the study of conservation of works of art, identification of species is not needed
as a rule, the descriptions of Professor Groom are much abridged here. He points out
that fruit-bodies in particular have various shapes within species.
The so-called ^c worms' which destroy wood are the larvae of beetles of the
order Coleoftera. In this large order only one group needs to be much considered
in relation to objects of art. This is made up of the furniture beetles (Anobiidae),
insects which inhabit seasoned wood. The larvae of the Anobiid beetles are usually
one tenth to one third inch long, are somewhat cylindrical and elongated in shape,
and are brownish in color. When full-grown, or developed as ^c worms/ they are
curved and wrinkled, have three pairs of legs and strong, biting jaws. The entire
life history of them is not known in all its points, but it is certain that, although the