CHKOMOGENIC FUNGI WHICH DISCOLOR WOOD. 85 



A. Species of Graphium with a secondary conidial 



STAGE WITH CONIDIA RESEMBLING THOSE OF SPORO- 

 TR1CHUM. 



Graphium ambrosiigerum n. sp. 



A species of Graphium was found growing in the gal- 

 leries of wood-boring beetles in the wood of Pinus Arizon- 

 ica Eng. This material was furnished by Dr. A. D. Hop- 

 kins in connection with the study of the relation between 

 ambrosia fungi and ambrosia beetles, a subject which is still 

 under consideration in connection with the study of such 

 beetles by Dr. Hopkins. Pieces were taken from the 

 stained wood in the interior of the block near a gallery, 

 and placed in test tubes of pine sapwood, which had been 

 sterilized after being moistened. From the mycelium in 

 the stained wood there grew out a white growth, bearing at 

 first the secondary then the primary conidia of Graphium. 

 Secondary conidia were found in some of the galleries 

 when the material was first examined, but were not recog- 

 nized as such at the time. The following are the cultural 

 characters of the fungus : — 



Mycelium and Secondary Conidia. 



When cultures are made with either the primary or sec- 

 ondary conidia on pine decoction agar, the spores generally 

 germinate in a few hours, and in two or more days colonies 

 may be noted with a white, sparse mycelium. At this 

 stage of growth, secondary conidia appear of the Sporofri- 

 chum-type, borne on erect, simple hyphae (pi. 8, f. IV). 

 These are hyaline, and oval in shape. After a few days, 

 portions of the mycelium assume a brownish color, and 

 from certain matted masses of filaments or stromata there 

 grow out tufts of erect, parallel hyphae (pi. 8, f. 6). 



