34 EXPEEIMENT STATION RECORD. 



that living protoplasm must be considered as a colloidal emulsion of lipoids in 

 hydrocolloidal media, the latter containing proteins and mineral salts. 



Growth and colloid hydratation in cacti, E. R. Loxg {Bot. Gaz., 59 {1915), 

 No. 6, pp. 491-497, figs. 2). — It was thought at first that the parallelism noted 

 by Borowiliow (E. S. R., 29, p. 420) between growth rate and hydratation 

 might be expressive of a general property of plant colloids. Experiments by 

 the author with Opuntia blakeana, however, gave opposite results as regards 

 hydrochloric and malic acids, both of which inhibited growth and hydratation. 

 The discrepancy may have been due in part, it is thought, to the stronger con- 

 centrations here employed. The action of alkali (sodium hydrate) upon swell- 

 ings was not so regular as that of acids, being possibly affected by the varying 

 acidity of the plant itself, which tended to neutralize to a greater or less degree 

 the alkali of the penetrating medium. 



In general, growth and swelling in these experiments paralleled rather 

 closely. Nutrient solutions exerted an accelerating effect over that observed in 

 distilled water, and hydrochloric and malic acids an inhibitory one, while the 

 effect of sodium hydroxid was irregular. 



The effect of some trivalent and tetravalent cations on permeability, 

 W. J. V. O.sTEKHorx {Bot. Gaz., 59 {1915), No. 6, pp. 464-473, figs. 7). — In con- 

 tinuation of previous investigations noted (E. S. R., 33. p. 328), the author 

 reports studies on the behavior of the trivalent cations lanthanum, cerium, 

 yttrium, iron, and aluminum, and on the tetravalent cation thorium, in which it 

 was found that they are able to decrease permeability to a marked degree. 



Atmometry and the porous cup atmometer, B. E. Lia'ingston {Playit World, 

 18 {1915), A'os. 2, pp. 21-30; 3, pp. 51-74, figs. 8; 4, PP- 95-111; 5, pp. 143- 

 149). — The author has attempted to put before workers in porous cup atmometry 

 the various matters requiring attention. The discovery, development, and 

 merits of the various forms of atmometer are discussed, as are also the con- 

 struction and use of the present standardized porous cup atmometer, its re- 

 standardization, and interpretation of the data obtained therewith. Reference 

 is made -also to the spherical porous cup atmometer used by Tower. 



FIELD CROPS. 



Division of forage plants. — Summary of results, 1914, M. O. Malte et ai.. 

 {Canada E.rpt. Farms Bui. 84 {1915), pp. 55).— This bulletin gives results of 

 testing varieties of forage plants at the various experiment farms of Canada 

 in continuation of work previously noted (E. S. R., 32. p. 532). The crops 

 include turnips, mangels, carrots, sugar beets, corn, alfalfa, red clover, timothy, 

 and other grasses. Some of the farms report breeding work with alfalfa, re<l 

 clover, and timothy. 



Green manuring and cover plants, R. W. Muneo {Agr. Bui. Fed. Malay 

 States, S {1915), No. 8, pp. 299-302). — Brief notes are given on trials of Clitoria 

 cajanifolia, Crotolaria striata, Crotolaria quinquifoUa, Canavalia en^iformi.^, 

 Centroseina pluincri, Mimo.m pudica, Mucmw sp., Tephrosia Candida, and T. pur- 

 purea as green manure and cover crops. Canavalia and Mucuna are mentione«l 

 as being of special value for use in the Fedorate<l Malay States. 



The improvement of grasses and forage crops {Rev. Vet. e Zootech., 5 

 {1915), No. 2, pp. 8S-i 08). —This gives results of cultural tests at the station at 

 Lages, Brazil, in ini4. 



Dry-farming investigations in the United States, L. J. Briggs {Rpt. Brit. 

 Assoc. Adv. Sci., 1914, pp. 263-282, pi. 1, figs. 7).— A paper reviewing the work 

 of the U. S. Department of Agriculture in dry-farming investigations. 



