120 BOTANICAL GAZETTE [JANUARY 
best suited to amounts of nitrogen running from 0.5 to 5 mg., and the sub- 
stance taken for determination should correspond to such quantities of nitrogen. 
The apparatus consists of small Kjeldahl flasks, fume absorbers, micro-burners, 
Ostwald pipettes, and small condensers, all readily obtainable or easily con- 
structed. Titration is used, rather than the colorimeter method, for the 
actual determination. A comparison of the determinations with the micro- 
and macro-Kjeldahl method shows that the micro method can be relied upon 
as reasonably accurate. The method will be exceedingly valuable with 
advanced classes in physiology.x—CHaArLEs A. SHULL 
Carbon nutrition—The ability of Glomerella cingulata to utilize certain 
pentosans and pentoses as a source of carbon has been investigated by 
Hawkrns.*_ He finds that arabin and xylan, and the derived sugars, arabinose 
and xylose, may be used as the sole source of carbon. When this fungus causes 
rot in apples, it decreases the total furfurol-yielding content of the apple, but the 
alcohol-soluble portion of the furfurol-yielding material is increased. This 
change indicates that the pentose sugars are split off from the more complex 
pentosans of the apple. The enzyme producing this change was sought. 
Filtered extract of the mycelium, acting under aseptic conditions, is able to 
change xylan to xylose, but it loses its power when boiled. It is clear, therefore, 
that a xylanase is present in the fungus or its extract which can hydrolyze 
xylan.— CHARLES A. SHULL. 
Plant formations of Canada.—In a brief bulletin of less than a score of 
pages Macoun and Matte” have outlined some of the most strikingly char- 
acteristic plant formations of Canada and noted their distribution and domi- 
nant species. It will serve to give some idea of the flora as a whole, and will 
indicate the wide diversity to be found, extending as it does from rich meso- 
phytic forests of conifers and deciduous trees to xerophytic grassland and 
Arctic tundras.—GEo. D. FULLER 
Californian plants.—An addition to our knowledge of the vegetation of a 
Murrayana dominate at different altitudes.—GEo. aa 
3 Haw s, L. A., The atilization of certain orga and compounds of pentoses 
by Clowada ¢ Aoiulele Amer. Jour. Bot. 2:375-388. 1 
7 Macowun, J. M., and Matte, M. O., The flora of Canada. Can. Geol. Survey. 
Museum Bull. 26:14, 1917. 
7 ParisH, S. B., An enumeration of the Pteridophytes and Spermatophytes of 
the San Bernardino Mountains, California. Plant World 20:163-178, 208-223, 
245-259. 1917. 
