1921] CURRENT LITERATURE 247 
regarding topography, climate, and soil, and the typical zonation of the vege- 
tation is outlined. These lakes are within the limits of the Picea Engelmanni 
forest, and the succession from the water’s edge includes moor, heath, and 
meadow associations. Different expressions of these types are to be seen 
about the various lakes, the moor, with its variations of moss moor, sedge moor, 
rush moor, willow moor, and meadow moor, usually occupying a large pro- 
portion of the area. Perhaps the most interesting of the communities is the 
heath, in which Gaultheria humifusa, Vaccinium caespitosum, and Kalmia 
microphylla are conspicuous. Any one of these small undershrubs or a com- 
bination of all three may dominate a comparatively narrow belt of vegetation 
midway between the lake and the forest. The several aspects of the asso- 
ciations are noted, the meadows affording the most brilliant and varied display. 
Maps, a ee and lists of species make the report graphic and 
exact.—GEo. ULLER. 
Accessory foods for plants.—BorTroMLEy?s has found several chlorophyll 
bearing water plants unable to develop normally in nutrient salt solutions not 
bearing — organic sia The plants worked on were as follows, 
naming th of their e organic material: 
na major and L. minor, Salvinia natans, ‘Asoile idea. and Limnobium 
sloniferum. 
The effective organic substanete were found to be present in- an auto- 
claved growth of Azotobacter chroococcum, crude nucleic acid derivatives from 
raw peat, and a water extract of bacterized peat..... n no case di 
organic substance supplied exceed 184 parts per million, while the 5 erage 
n 
BotroMLeEy and of several other investigators who have recently published 
their results, it appears that accessory foods may have considerable significance 
in plant development, as they have very great significance in animal nutrition 
and growth.—Ww. CROCKER. 
Rate of Menaintddaingrs in the field —M cLEAN* of the Dons beara = 
worked up 
by leaves i in ede open. There is certainly great need of such methods for deter- 
mining photosynthetic rates as well as the rates of other plant processes occur- 
stores more than twice as much starch in the ears as his neighbor’s corn for 
8s BoTTOMLEY, W. B., The effect of organic matter on the bodies of various water 
plants in culture solutions. Ann. Botany 34: 353~305- 1920: 
36 McLEan, F. T., Field studies of the carbon 
Ann. Botany 34:367-389. 1920 
f coconut leaves. 
