64 MISSOURI BOTANICAL GARDEN. 



sects feed on the conidial stage of Ceratostomella, especially 

 one or more species of ambrosia beetles aud a number of 

 mites infesting their channels in the wood ; but proof is 

 yet lackiug on this point. The constant occurrence of this 

 fungus in the channels of a number of wood boring beetles 

 indicates that the conidia or the ascospores must be carried 

 in some manner by these insects. Hopkins* describes 

 some of these beetles in a bulletin of the U. S. Department 

 of Agriculture, and vonSchrenkf describes how C . pilifera 

 follows the channels of wood-boring beetles in Pinus 

 ponderosa. The writer has made similar observations on 

 Ceratosmella in its penetration of Pinus ponderosa, P. 

 Arizonica, P. ecliinata and P. Virginiana. 



Although the genus Oeraiostoma is very closely related 

 to Ceratostomella none of the species of Ceratostoma have 

 been found in connection with the blue stain of wood. In 

 the course of the present investigation stained wood has 

 been collected from a large number of localities, including 

 wood from trees and shrubs of the following genera : Abies, 

 Acer, Fagus, Fraxinus, Liquidambar, Liriodendron, 

 Pinus, Rubus, Ulmus, Vitis and Wistaria. A number of 

 species and varieties of Ceratostomella have been identified, 

 cultivated and proved to be wood-bluing fungi. Ceratos- 

 iomella pilifera has been found far more prevalent than 

 other species. As the conidial stage of this species was 

 first discovered by the writer and the description has never 

 been published, it will now be given. It is taken from the 

 results obtained from a very large number of pure cultures 

 grown and studied over a period of nearly four years. 



Ceratostomella pilifera (Fr.) Wint. 



This fungus has been isolated in cultures taken from 

 stained wood from a number of species of Pinus taken 

 from nearly every region of the United States. It pene- 



* Hopkins, A. D. Bull. Div. Ent U. S. Dept. Agr. 32: 9, 10. 

 f Von Schrenk, H. I. c. 



