THE * 4 BLUING AND THE 44 KED EOT OF THE PINE. 



becomes equally rapid. The blue color appears around the beetle 

 holes soon after the entrance of the "blue" fungus. Usually it forms 

 two rings extending from the hole along the wood fibers. Various 

 stages of this first appearance of the color are shown on PI. IX. The 

 spread of the "blue" fungus within the wood, through the agency of 

 wood-boring beetles, is an occurrence frequently found in many conif- 

 erous woods. The central figure at the bottom of PI. IX is from a 

 photograph of a log of western hemlock found in the Olympic Forest 

 Reserve, in Washington, which shows an even more striking case of 

 the spread of Ceratostomella from holes made by Gnathotricus ocd- 

 dentalis Hopkins MS. This particular piece of wood was cut from 

 a fallen trunk, about 6 inches in from the bark. 



FRUITING ORGANS OF THE ;4 BLUE" FUNGUS. 



The "blue" fungus forms its fruiting bodies on the surface of the 

 wood in which it is growing. Air seems to be necessary for the for- 

 mation of the fruiting bodies. A good deal of moisture in the sur- 

 rounding air is necessary likewise. No fruiting organs are formed in 

 dry air. In the forest they occur in the cracks formed when a blued 

 trunk is broken off, on broken branches, and at such other points as 

 are exposed to the air. So far the writer has been unable to find the 

 perithecia of Ceratostomella on the surface of standing trunks under 

 the bark, although a diligent search has been made for them at all 

 seasons for two years. When, several months after the beetle attack, 

 the bark becomes loose, so that it separates from the wood, a space 

 is left between the bark and wood. In this space numerous fungi 

 develop in quantities, among others a species of Altemaria which lines 

 the pupal chambers of the Dendroctonus, and a species of Verticillium. 

 The whole atmosphere of this region is surcharged with moisture, and 

 yet the ' ' blue " fungus does not fructify here, for there is probably 

 not enough air. 



The black perithecia of the "blue" fungus, Ceratostomella pilif era 

 (Fr.) Winter, are familiar objects on blued boards or shingles, where 

 they occur in thousands side by side. The perithecia are formed 

 within a few hours when the conditions are favorable. At various 

 points on the surface of the wood, in some instances out of every 

 medullary ray, masses of hyphas grow out forming a dense mass which 

 gradually develops into an egg-shaped body (PL VII, 4). The surface 

 of the young perithecium shows irregular polygonal markings, which 

 gradually become indistinct as the perithecium turns jet black almost 

 to its tip. At the tip of the young perithecium a number of hyphse 

 grow out parallel with one another (PI. VII, 4) in a direction perpen- 

 dicular to the substratum. They remain colorless at the tip. These 

 hyphge grow in length with remarkable rapidity and form a long 



