1917J CURRENT LITERATURE 331 



The grains, barley and oats, showed little effect on the quantity of straw, 

 but a noticeable increase in seed production occurred on plants grown on the 

 soil used (Miami silt loam) . 



Elemental sulphur, added as flowers, was usually toxic even in the presence 

 of calcium, probably because of its incomplete oxidation to sulphites. Where 

 bases are deficient, the toxicity may be due to accumulation of sulphuric acid 

 from the complete oxidation of the sulphur. — Charles A. Shull. 



British Columbia forests. — Mount Robson, British Columbia, situated 

 at practically the present northern known limit of the continental divide, has 

 been visited by Cooper 22 and found to possess 2 climax forest types, one for 

 each of 2 climatic zones. Up to an altitude of 1000 m. the forest is of the 

 Pacific Coast type, with a dominance of Thuja plicata. Picea Engelmanni is 

 next in abundance, and is followed by Abies lasiocarpa, Tsuga heterophylla, 

 and Pseudotsuga mucronata. The undergrowth shows such truly mesophytic 



iflora, Moneses unifl 



albifl 



2000 



forest of Picea Engelmanni, Abies lasiocarpa, and Pinus albicaulis. In the 

 undergrowth Menziesia ferruginea, Cornus canadensis, and several species of 

 Pyrola are conspicuous. The successions upon rock surface, talus, moraine, 

 and shingle flat are noted, those of the two last in most detail. Upon the 

 moraine Dry as octopetala and Arctostaphylos rubra are followed by shrubby 

 species of Betula and Salix, leading to the third stage, which is the climax 

 forest. A similar set of stages is found upon the shingle flat, although here, 

 probably because of the lack of any fine soil material, the succession advances 

 much less rapidly than upon the moraine. 



While Cooper expresses regret at the few data available for this study, 

 it will be welcomed as giving an insight into the vegetation of an almost 

 unknown region.— Geo. D. Fuller. 



Large trees. — A recent contest for two prizes of $100 each, offered through 

 the Journal of Heredity, 2 * for photographs and data regarding the largest trees 

 in the United States, barring conifers, resulted in photographs of 337 trees. 

 The prize for the largest non-nut-bearing tree was won by a Platanus occiden- 

 tal near Worthington, Indiana, with a circumference, 5 ft. from the ground, 

 of 42 . 25 ft., and a height of about 150 ft. The largest nut-bearing tree in the 

 competition was a Quercus lobata on the foothills of the Sierra Nevada Moun- 

 tains, in San Benito County, California, with a circumference of 37 . 5 ft. and a 

 height of 125 ft. The largest specimens of other species were as follows: 

 Ulmus americana at Morgantown, West Virginia, with a circumference of 33 



22 Cooper, W. S., Plant succession in the Mount Robson region, British Columbia. 

 Plant World 19:211-238. figs. S. 19 16. 



23 Photographs of large trees. Jour. Heredity 6:407-429- M>*S- 



