a cane jBeld has been burned over, the very striking orange-pink 

 clumps thickly clustered on every available bit of material over acres 

 and acres make a most striking sight. Where the trash is not burned 

 it very rarely occurs, and never more than as small scattered sporo- 

 dochia at best. The fungus also causes a mold of bread much more 

 serious than that due to Aspergillus or Mucor. In the laboratorj^ it 

 evinced a great ability to grow into other cultures and culture media 

 through the cotton plugs and after one experience, during which con- 

 siderable difficulty was had in getting rid of it, it has never been 

 brought into the laboratory again. 



Trichoderma lignorum (Tode) Harz. 



Forming more or less cottony, finally powdery sporodochia, sub- 

 circular to indefinite, up to 5 mm. diameter, white at first, then deep 

 green with white margin ; hyphae interwoven, subcompact, filiform, 

 continuous, fertile hyphae erect, 2-4 lageniform branches or conidial 

 bearing organs; conidia formed in globules of 8-10, spherical to 

 elliptical, light green, 1.^3 X 3-4.3 mu ; heads averaging 7 mu. 

 Description amended, after Saccardo. 



Porto Rioo. — On dead and dying cane stalks and leaves, Aug., 

 1912, 4548, 4667, 4666, Jan., 1914, 1173, Jan., 1914, 1201, Oct., 1914, 

 2275, July, 1915, 2831, Sept., 1915, 3073. Apr., 1917, 6402, June, 1917, 

 6561. Very commonly observed in all parts of the Island. First 

 determination by :\Irs. F. AY. Patterson. (PL XXI, fig. 4; pi. XXX, 

 fig. 6, 10-12.) 



This is an exceedingly common form in and about cane fields and 

 has appeared a great number of times in damp chamber tests and in 

 cultures. It is especially to he found on the lower leaf-sheaths, in 

 connection with Cerospora, Sclerotium, and other fungi, at times 

 apparently acting as a wound parasite aiding in the death of the 

 leaf-sheaths. Because of the great frequency of its occurrence in 

 the course of laboratory studies on the cane cankers of the mottling 

 disease, internal rots of various types, etc., attempts were made to 

 prove its parasitism, if any, by inoculations. Negative results were 

 obtained, it not even being capable of producing red striping, hence 

 it is now considered only as a saprophyte. 



Arthrinium saccharicola Stevenson sp. nov. 



Forming small black masses on the substratum, 1-1.5 mm. diam., 

 not coalescing; sterile hyphae scanty, recumbent: fertile-hyphae si^n- 

 ple, suberect to erect; aggregate, hyaline, with broad, black, nu- 

 merous septae, swollen at base, about 100 mu. long; conidia sessile, 



223 



