1918] AGRICULTUEAL BOTANY. 23 



" More boron was absorbed by the plants from the borax than from the 

 coleraanite plats, although only minute amounts of boron were absorbed by any 

 of the wheat plants. The 1916 samples of straw and grain contained more 

 boron than the 1914 and 1915 samples. In all samples a relatively uniform 

 distribution of boron in the straw and grain was found. 



"A yellowing of the young plants was observed the first year (1914) on 

 the borax plat. This directly followed a heavy application of borax manure 

 to the plat, and the sample of soil from this plat taken nine months later 

 showed the presence of soluble boron. In no other soil sample was any sol- 

 uble boron found. Apparently the added borax is gradually combined in an 

 insoluble compound and so distributed that the upper 6 in. of soil show little 

 total boron after three yearly additions of borax. There were no evidences of • 

 any cumulative action of boron in the soil. It was apparently the soluble 

 boron, not the total boron, in the soil that produced injury to the wheat 

 plants." 



Domestic manures and related substances, W. Thomas {Pennsylvania Sta. 

 Rpt. 1915, pp. JtlS-Ji25). — Analyses of cow and horse manure, and composts 

 therefrom ; sheep and goat manures ; spent manures from mushroom beds ; hen, 

 duck, and pigeon manures, and composts therefrom ; bat guano ; and night 

 soil are reported and discussed. 



AGRICULTURAL BOTANY. 



Plant succession on abandoned roads in eastern Colorado, H. L. Shantz 

 {Jour. Ecology, 5 {1911), No. 1, pp. 19-1,2, pi. 1, flgs. 22).— The author has 

 made a study of some roads on the high plains in eastern Colorado and var- 

 ious phases of their formation, but more particularly of their obliteration, in 

 an attempt to determine the relations of the vegetation to the factors affecting 

 its prevalence, persistence, suppression, reestablishment, and development. 



The natural vegetation at Akron, Colo., formerly discussed by the author 

 (E. S. R., 24, p. 722) as the grama-bufCalo grass association of the short-grass 

 formation, the principal type of the central portion of the Great Plains, con- 

 sists largely of grama grass {Bouteloua gracilis [B. oUgostachya]) and buf- 

 falo grass {Buchloe [BulMlis] dactyloides) . It is said that an area if aban- 

 doned after cultivation will reestablish this association in from 20 to 50 years. 

 The stages passed through in attaining this final result are described and sum- 

 marized. An early weed stage of plants which are comparatively large but 

 so scattered as not to compete for soil moisture is followed by a late weed 

 stage, a dense growth of stunted plants, the total growth utilizing to the limit 

 the available water. Next comes a temporary grass stage usually characterized 

 by Schedonnardus, a short-lived perennial able to shut out the annuals. by its 

 power of quick appropriation of the surface water supply. Gutierrezia, utiliz- 

 ing the moisture of the deeper soil layers, gradually replaces Schedonnardus and 

 is in turn replaced by the long-lived surface feeding Buchloe. Bouteloua re- 

 seeds very slowly and requires a number of years to attain the dominance 

 somewhat quickly attained by Buchloe. 



Cold resistance in spineless cacti, J. C. T. Uphof {Arizona Sta. Bui. 79 

 {1916) , pp. 115-144, pis. 2, flgs. 11 ) . — After a brief discussion of cold resistance 

 in spineless cacti by J. J. Thornber, the author gives an account of field and 

 laboratory studies on the relation between the morphology and physiology of a 

 number of introduced and indigenous species of spineless cacti and their re- 

 sistance to cold. 



