4 BULLETIN 1053, U. S. DEPARTMENT OF AGRICULTURE. 
Lenzites sepkui-a has been studied as a destroyer of coniferous tim- 
bers in buildings by Falck (15) in Europe and out of doors by Spauld- 
irig (58) in this country. Its importance in the destruction of mill 
roofs was suspected by Hoxie (24-) in 1915, and since then he and 
others, including the writer, have found it fruiting quite commonly 
and doing much damage in such places. (PL I, figs. 1 and 2.) Len- 
zites trabea has been reported by Blair (./) as destroying weave^shed 
roofs. This species, though usually found upon hardwoods in nature, 
probably occurs more commonly and is more destructive to coniferous 
lumber under mill conditions than has yet been reported. The writer 
has found it fruiting upon yellow pine and spruce roofs. (PI. I. 
figs. 3 and 4.) 
Trametes serial is has been found upon some of the more badly de- 
cayed roofs along with other fungi (PI. I, fig. 5 ; PL II, figs. 1 and 2) , 
but within buildings it is usually upon basement timbers. This fungus 
generally occurs in the resupinate form and also forms abortive struc- 
tures. 
Fomes roseus is found within mills upon beams in moist basements 
(PL II, fig. 5) . The annual form is the one of common occurrence, and 
whether or not the perennial form also occurs is not certain. Many 
mycologists consider the annual form as a distinct species, Trametes 
carnea. 
Lentinus lepideus has been found upon roof timbers under very 
moist conditions and in basements (PL II, figs. 3 and 4). It also 
occurs in Europe on building timbers (cf. Mez, 35; Falck, 17.) Its 
destructiveness to structural timber in the open is well known. 
BASIDIOSPORES. 
SOURCES OF BASIDIOSPORE MATERIAL. 
The basidiospores used were obtained for the most part from fruit 
bodies collected in the field. Those of Lenzites sepiaria were from 
various collections in Wisconsin. The spores of Lenzites trabea were 
obtained from fruit bodies upon pulpwood bolts, collected in Penn- 
sylvania, by F. J. Hoxie. The basidiospores of Trametes seri- 
alis were obtained from fructifications on Some rotten timbers (re- 
moved on account of decay) from the pulp-and-paper section in the 
Forest Products Laboratory and placed in the forest-pathology 
greenhouse. From two or three small sporophores formed in No- 
vember, 1919, sufficiently large numbers of spores were obtained to 
last through two winters of experimentation. Sporophores of the 
annual form of Fomes roseus were collected upon tamarack (Larix 
laricina) logs in Wisconsin and red spruce (Picea ruhens) in New 
Hampshire. The spores of LenHnus lepideus were obtained from 
sporophores collected by Mr. Hoxie in a cotton mill in Massachusetts. 
