76 MISSOURI BOTANICAL GARDEN. 
gus occurs throughout the Northern States on coniferous 
trees, and, moreover, that it never occurs except in the 
beetle holes.* In the extreme west it is found on Pseu- 
dotsuga douglasit and Sequoia sempervirens. The latter 
tree is remarkably free from the attacks of fungi and 
would also be unaffected by this one were it not for these 
rather insignificant looking insects. Polyporus pinicola t 
also is known to gain entrance to trees by means of the 
holes of wood-boring insects. This is a particularly de- 
structive wood-rotting fungus, and is responsible for much 
damage in lumber regions. In many cases there seems to 
be a direct relation between the distribution of the blueing 
fungus, Ceratostomella pilifera (Fr.) Wint., and the 
attacks of the wood-boring beetle, Dendroctonus ponde- 
rosae, on the wood of standing pine trees. Instances are 
also known where this fungus spread from the holes made 
by another wood-boring beetle.{ Just what is the exact 
truth of the matter has not yet been determined in a satis- 
factory manner. As our knowledge of the fungi increases 
it is inevitable that many similar cases will be discovered. 
EXPLANATION OF PLATES. 
From photographs by the writer. 
Plate 25.—1, View of a rotted log with Flammula sapineus growing in 
holes made by wood-borers. On the left side is seen a fungus growing 
out of a horizontal hole and showing the edges of the hole just below the 
stem. On either side are empty holes. 2, Specimen of Flammula 
sapineus in its natural position in the hole, slightly reduced. This gives 
a very good idea of the peculiar appearance of the fungi thus located. 
8, Section of a log showing the character of the holes, the material con- 
tained therein, the extent of the mycelium into this material, and a group 
of three fungi, Flammula sapineus, growing from a single hole. The 
fungi are badly dried. 
Plate 26.— 1, General appearance of alog with a specimen of Flammula 
* MSS. in preparation. 
¢ Bull. Div. Veg. Phys. & Path., U. S. Dept. Agric. 25: 14. (1900.) 
{ Bull. Bureau Plant Industry, U. S. Dept. Agric. 36: 20. (1903.) 
