1919] AGRICULTURAL BOTANV. M f J 



treated with certain staining materials, a quasi predpltatUn occurs, t ho author 

 bas studied the effects of a considerable series of dye materials oo the mucilage 

 of Opuntia, Abutilon, GESnothera, peacb pericarp, and the products >>( cell-wall 

 hydrolysis during ahsrission. Tiie results axe briefly Indicated 



The mucilage of Opuntia, Abutilon, and CEnothera, F. K. L&OYD {Carnegie 

 Inst. Washington Year Book, 17 (1918), pp. 71, 72). —The mucilages of several 

 plants are discussed as to characters and behavior under conditions or treat- 

 meats which are indicated. 



Pine needles, their significance and history, J. Ihmkkmiy (Hot. <!<i:., 66 

 (1918), No. 5, pp. 439-454, figs. 29) —A review of the morphology, development, 



and physiology <>f pin<> needles and related structures coneludes with the state- 

 ment that morphological variations are but the result of physiological varia- 

 tions, different forms of the different phyllodes of pines, juvenile leaves, scale 

 leaves, fertile leaves (male and female flowers), and assimilatory organs, 

 differing widely but being shown by abnormal transitory forms to be really 

 different distorted features of a generalized ancestral organ. Needle- are the 

 physiological leaves of pines, though they may last for several seasons, being 

 specialized to meet unfavorable conditions. 



The present state of the study of anthocyanin, J. Beat.tvf.kik < Re©, <i>'n. Hci 

 29 (1918), Nos. 20, pp. 572-579, fig. 1; 21, pp. 604-612) .—The first part of this 

 contribution deals with findings and views of various authors as to the origin, 

 distribution, and relations of anthocyanin as regards heredity and function. 

 The second part deals mainly with its chemical constitution. 



The production of anthocyanins and anthocyanidins, III, A. EC, EjVKBBOT 

 il'roc. Roy. Soc. [London], Scr. B, 90 (1918), No. B 628, pp. 251-265).— Although 

 this work, which is a continuation of that previously noted (B. S. K.. 33, p. 328 I, 

 has been suspended in the preliminary stage of its present aspects, the author 

 presents some findings and inferences for comparison with results of recent 

 work by other authors. Evidence is discussed which is considered to strengthen 

 the probability that anthocyan pigments are formed in plants and flowers 

 naturally from flavonol glucosids, and that flavonols may give rise to antho- 

 cyamldins. It is claimed that the anthocyanin described in this report is 

 identical with violanin. 



Effect of certain compounds of barium and strontium on the growth of 

 plants, J. S. McIIakoue (Jour. Agr. Research [U. &], 16 (1919), No. 7. /</>. U 

 194, pi- i). — The author gives the results of experiments carried on at the Ken- 

 tucky Agricultural Experiment Station to determine the effect of barium and 

 strontium on the growth of plants. Cowpeas, oats, spring and winter wheat, 

 corn, and soy beans were grown in barium-free sand to which the necessa r y 

 plant foods were added, together with the desired compounds of barium and 

 strontium. 



From the results obtained, it is concluded that barium compounds in the 

 absence of calcium carbonate are poisonous to plants, but in the presence of 

 an excess of calcium carbonate barium carbonate exerts a stimulating influ- 

 ence on the growth of the plants studied. No tendency was observed for 

 barium to replace calcium in the growth of plants when calcium carbonate 

 was omitted from the plant-food ration. Strontium compounds in most in- 

 stances gave larger increased yields than barium compounds. Strontium car- 

 bonate, it was found, can not be substituted for calcium carbonate in the 

 growth of plants under the conditions studied, though strontium carbonate 

 is less toxic to the growth of plants in the absence of calcium than is barium 

 carbonate. It is claimed that the compounds of neither of the elements 

 studied can be regarded as important plant foods, although the presence of 

 small amounts of the carbonate of each gave increased yields in most in- 



