MISSOURI BOTANICAL GARDEN BULLETIN 13 
In the limited space of this report it is not possible to in- 
clude abstracts of the various published investigations of the 
year, but brief indications may be given of the general na- 
ture and significance of the papers. 
Allen, E. R. (Ann. Mo. Bot. Gard. 6:1-44) has applied to 
a physiological study of conditions affecting the soil nitrogen- 
fixing organism, Azotobacter chroococcum, the view that phos- 
phorus nutrition and active acidity may have been important 
determining factors in the diverse results obtained by earlier 
investigators. By the use of colloidal solutions and a mechan- 
ical agitator for the solution cultures containing insoluble 
precipitates considerable light has been thrown upon the im- 
portant growth factors for this organism. 
Allen, E. R., and Davisson, B. S. (Ann. Mo. Bot. Gard. 
6 :45-48) describe an all-glass nitrogen apparatus of Pyrex 
glass in which rubber stoppers are eliminated and there is 
effected efficient scrubbing of the entrained alkali from the 
steam. 
Burt, E. A. (Ann. Mo. Bot. Gard. 6:143-145) adds to 
his earlier communication notes on five species of Merunus 
in North America. 
Burt, E. A. (Ann. Mo. Bot. Gard. 6:171-174). Hebeloma 
hortense, a new species, collected in flower beds of the Mis- 
sour! Botanical Garden, proves to be an edible mushroom of 
desirable quality and of distinctive flavor 
Burt, E. A. (Ann. Mo. Bot. Gard. 6:175-177). A new 
Protomerulius is described and the species named after the 
late Professor W. G. Farlow This species is characterized by 
pores more minute than those of any other known fungus. 
The plant as a whole is very delicate and unusual. 
Burt, E. A. (Ann. Mo. Bot. Gard. 6:252-279), continuing 
his monograph of the Thelephoraceae of North America, in- 
cludes five genera, namely, Tulasnella, Veluticeps, Myecobonia, 
Kpithele, and Lachnocladium, in the present article. Two 
new species (one in Epithele and one in Lachnocladium) are 
established and one species (Pterula setosa) transferred to 
Lachnocladium by Saceardo in 1880, is excluded. 
Dodge, C. W. (Ann. Mo. Bot. Gard. 6:71-92) has made a 
biochemical study of the amino-acid, tyrosin, as it occurs in 
eertain fleshy fungi. His results suggest that the tyrosinase 
reaction is not a deamination and that the tyrosin molecule 
becomes more complex prior to decomposition. 
