94 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 still 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 by the wind. It was thought that the bark beetles might 
be instrumental in carrying the spores into their holes. This they 
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 (Dendroctonus) 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 any 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 /elotium xruginosum (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 
