1919] FIELD CROPS. 29 



It appears that the water requirements of the cacti are easily satisfied. 

 The studies on the effect of water content and temperature on carbohydrate 

 equilibrium have substantiated and elaborated tlie former findings. No 

 simple or constant relation was established between the rate of carbon dioxid 

 elimination and the carbohydrate supply, nor was respiration very definitely 

 associated with any group of carbohydrates, although a certain negative 

 correspondence is pointed out. It is thought that under certain conditions 

 cacti possess the power of utilizing polysaccliarids and aplastic material. The 

 formation of pentosans is intimately associated with this condition in ways 

 which are noted in connection with further studies now in progress. 



Acidity of mesophytic and succulent fomis of Castilleia, Ericameria, and 

 Erigeron, H. M. Richards {Carnegie Inst. Washington Year Book, 11 {1918), 

 pp. 6-'t, 65). — Some forms of variation in succulence and acidity were determined 

 and are discussed, this work dealing with Ericameria ericoides, C. JatifoUa, 

 and Erigeron glaucus. 



The acclimatization of plants, G. L. Sutton {Advisory Council Sci. and 

 Jndns., Aiist., Bui. 7 {1918), pp. 88-95). — In addition to a discussion by the 

 author and others of the naturalization and acclimatization of plants, an 

 account is given of plans and measures for the organized control of activities 

 connected with the introduction of plants into portions of Australia. 



FIELD CROPS. 



Dry farming in Arizona, A. M. McOmie, C. B. Fii^lerup, and L. L. Bates 

 (.4r/^ona Sta. Bui. 8Jf {1918), pp. 491-642, figs. ^7).— This bulletin comprises a 

 rather detailed discussion of the geology and soils of the State, temperatui'e 

 and atmospheric movements in the region, the principal dry-farming sections 

 of Arizona, Indian agriculture in Arizona, and farming operations of early 

 white settlers, together with a digest of the results of several years' experi- 

 mental work on the Snowflake, Prescott, and Sulphur Spring Valley dry 

 farms, dealing with cultural methods, choice of crops, variety tests, live- 

 stock feeding, silage production, and observations on cooperative management 

 between dry-farming and range stock interests. Results secured on another 

 farm in the Sulphur Spring Valley have already been noted (E. S. R., 29, pp. 

 725, 735). 



It is stated that in the southern part of the State, at an altitude of 4,000 

 ft. and with a long growing season, Kafir corn, Club-top sorghum, milo maize, 

 and tepary beans gave the best results, while in the northern part, under 

 less stringent conditions, quick growing, drought-resistant varieties of corn, 

 Sudan grass for hay, potatoes, several varieties of beans, and even orchard 

 fruits were also found to be suited to dry farming. The production of silage 

 is deemed to be of considerable importance, particularly in connection with 

 the range cattle industry, it being maintained that large areas of semiarid 

 lands within the State might be developed to advantage in cooperation with 

 the range stock interests. 



Dry farm crop rotations and cultural methods, A. Atkinson and L. F. 

 GiESEKER {Montana Sta. Circ. 81 {1918), pp. //9-58).— This comprises a brief 

 popular account of work previously noted (E. S. R., 39, p. 131). 



Keport of [field crops] work at Fairbanks Station, C. C. Geokgeson and 

 M. D. Snodgkass {Alaska Stas. Rpt. 1917, pp. 28-30, 57-59, 61-70, 85, 86, pis. 

 3). — The continuation of work during 1917 along the same general lines as 

 previously noted (E. S. R., .39, p. 125) is described. Continued dry weather 

 resulted in poor germination at the time of seeding and led to the production 



