'32 EXPERIMENT STATION EECORD. 



[Vol. 38 



Some unusual features of a subarctic soil, H. E. Pulling (Johns Hopkins 

 Univ. arc, «. ser., No. S (1911), pp. 1S8-190).—A prelimiuary survey of the 

 ecological features of subarctic forests in northern Manitoba has yielded in- 

 formation that emphasizes the need of including the physical root environment 

 in an ecological study of these regions. 



The soil of the spruce forest, the characteristic type of this region, is covered 

 chiefly with sphagnum, which holds large quantities of water, except in hillside 

 forests, in which case the soil underneath the moss, due to conditions which are 

 explained, is usually dry and may blow as dust. Roots penetrate this dry layer 

 only to a slight extent, although organic deposits occur as far down as the 

 frost line. No explanation is given of the mode of origination of these deposits, 

 nor of the fact that the soil in the dry layer is often flocculated to such a degree 

 that it resemble;^ a mass of small clay pellets, retaining its .spherulate character 

 even after it has been soaked with water. 



The westei-n flower guide, C. F. Saundebs (Garden City, N. Y.: Doubleday, 

 Page d Co., 1911, pp. 286, figs. 250).— Brief nontechnical descriptions, accom- 

 panied by colored drawings, are given for the ready identification of 250 of 

 the more common wild flowers found from the Rockies to the Pacific coast. 



Flora of the Rocky Mountains and adjacent plains, P. A. Rydgeeg (New 

 York: Author, 1911, pp. XII +1110). —This is a manual of the flowering plants, 

 ferns, and their allies of the Rocky IMountain region, the area covered embrac- 

 ing Colorado, Utah, Wyoming, Idaho, Montana, Saskatchewan, Alberta, and 

 neighboring parts of Nebraska, South Dakota, North Dakota, and British Co- 

 lumbia. 



Marking microscope slides, Maey K. Bryan (Science, n. ser., J^l (1918), 

 No. 1201, p. 111).— The author briefly describes the use of a carborundum pencil 

 for the marking of microscope slides. 



FIELD CROPS. 



Relation of size of seed and sprout value to the yield of small grain 

 crops, T. A. KiESSELBACH and C. A. Helii (Nebraska Sta. Research Bui. 11 

 (1911), pp. 3-13, figs. 7).— The authors report exten.sive investigations with 

 wheat and oats to determine the extent to which differences in size of seed 

 may affect the crop produced, superior yielding power having been frequently 

 attributed to extra large seed. Sprout value is described as " the muisture- 

 free weight of the maximum plant growth derived from the seed when planted 

 and grown in a nonnutritive quartz medium and in absolute darkness." 



The experimenf&l work embraced the following lines of study : The relative 

 sprout values of different grades of seed wheat, the relation of size and sprout 

 value of seed to yield at different depths of planting, the effect of competition 

 between plants grown from seeds markedly different in size and sprout value, 

 the influence upon total yield of competition between large and small seeds, the 

 effect of competition between varieties, the relation of size of seed to yield of 

 wheat when various grades are planted alone in equal numbers, the reasons why 

 small seeds yield less per acre than large seeds when planted in equal numbers 

 at the normal rate for the large seed, the relative yields from large and small 

 seeds when planted in equal numbers and at equal weights, and the relative 

 yields of seed grades of wheat and oats as separated by the fanning mill. A 

 historical summary of the experimental work of other investigators on the 

 yielding qualities of large and small or light and heavy seeds Is presented, 

 including tests with winter and spring wheat, oats, barley, and rye. The loss 

 of seed substance through respiration was determined by means of an especially 



