24 THE "BLUING" AND THE "RED ROT" OF THE PINE. 



ascospores leaves no doubt as to their being- a stage of the "blue" 

 fungus. Cultures made from these conidia developed a mycelium on 

 which both conidia and perithecia appeared. Work with these conidia 

 is .-till in progress and a report upon the results accomplished is to be 

 published in full at a later date. 



In four to five days in good growing cultures on rich pine agar or on 

 sterile pine blocks the older threads of the colorless mycelium begin 

 to turn brown, and at the end of seven to nine days young perithecia 

 begin to form. These are at first hyaline and change rapidly from 

 brown to black. They mature quickly, and at the end of from twelve 

 to eighteen days some will be found ejecting the ascospores. In twenty- 

 one days nearly all perithecia in a culture will be mature. 



DISSEMINATION OF THE SPORES. 



The sudden appearance of the "blue'' fungus on lumber piles and 

 over large areas at once, and its simultaneous appearance within the 

 trunks of the pine trees seem to point to the distribution of the spores 

 of the fungus b\ r the wind. It was thought that the bark beetles might 

 be instrumental in carrying the spores into their holes. This the} 7 

 might do by having the spores adhering to their bodies or by feeding 

 on the spores and depositing these in their holes. To test these hypoth- 

 eses, beetles were placed in tubes of melted pine agar, thoroughly 

 shaken, and then plated. Quite a number of beetles were dissected 

 and cultures were made, using their alimentary canals, as well as some 

 of their feces, as infecting material. In none of these cultures did any 

 "blue" fungus appear. A very characteristic bacterium was obtained 

 from the alimentary tracts, but no Ceratostomella. A number of live 

 beetles (Dendroctonw*) were allowed to walk about on pine agar plates, 

 but no "blue" fungus developed. These trials are by no means to be 

 regarded as conclusive, for they were not exhaustive. They are to 

 be repeated on a larger scale this winter and in the summer when 

 the beetles emerge. The number of perithecia developing on dead 

 sticks and in cracks is sufficient to account for an} T infection which 

 takes place in the Black Hills forest. This applies with equal force 

 to all regions where the "blue" fungus occurs. 



The months of May, June, July, and August are the ones during 

 which the most rapid development of this fungus takes place. 



THE BLUE COLOR. 



Wood in which the mycelium of Ilelotium seruginosum (and prob- 

 ably of other "green" fungi) grows turns green very soon after the 

 fungus gets into the wood. As shown by Vuillemin and others, the 

 green color is due to a substance formed as a product of metabolism 

 of the fungus, which is deposited in the form of regular granules in 



