SCHIZOTHYRIUM 285 



hail and by the breaking of the branches by snow and ice, 

 also expose the cambium to fungus spores.' 



Like D. calydna, D. resinaria is a wound parasite, and I 

 have elsewhere shown that it frequently enters through wounds 

 made by another parasitic fungus called Exosporium. The 

 spores also germinate on the resin oozing to the surface 

 through punctures made by the larch aphis (Chermes abietis, 

 L.) Soon after infection the outer bark breaks away in frag- 

 ments, owing to the pressure of the rapidly growing inner 

 bark, which becomes hypertrophied. The depression caused 

 by the work of the fungus continues to increase in size, and 

 the edges of the wound become more swollen than in larch 

 canker, and the wound more frequently girdles the branch. 

 The flow of resin is more copious than in larch canker, and 

 large gum-pockets are formed in the wood. Successful 

 inoculations resulting in the production of ascophores on 

 spruce and larch have resulted from placing a fragment of 

 resin containing mycelium into a puncture in the bark. A 

 similar result followed the placing of ascospores in the minute 

 cavity occupied by Chermes lands or Larix sibirica (Ledeb.). 



The ascophore in D. resinaria closely resembles that of 

 D. calydna, but is more narrowed below into a stem-like base, 

 and the disc is of a paler yellow colour. The essential 

 character of D. resinaria is the very minute, subglobose 

 spores, 3 X2-2'5 /*. Conidia elliptic-oblong, 2X1 p. 



Preventive remedies same as for larch canker. 



Anderson, A. P., Bull. Torrey Club, 29, p. 23 (1902). 

 Massee, G.,Journ. Board Agric., Sept. 1902. 



Dasyscypha subtilissima (Sacc.) has been observed forming 

 a canker on the living bark of Abies pectinata (D. C.), and on 

 Larix europaea, (D. C.), but is not injurious at present. 



Ascophore resembling that of D. calydna spores 8-ioX 



2/U 



Dasyscypha abietis (Sacc.), parasitic on the bark of Picta 

 excelsa (Link.) Ascophore indistinguishable from that of 

 D. calydna ; spores elliptic, ends acute, becoming i-septate, 

 12-14x3 ^ ; paraphyses longer than the asci. 



SCHIZOTHYRIUM (DESM.) 



Ascophores more or less immersed in the substance of the 

 host, opening by a longitudinal slit or by slits radiating from 



