632 EXPERIMENT STATION RECORD. 



The admission o£ anilin colors into living plant cells, E. Kxjstee (Jahrh. 

 Wiss. Bot. [Pringsheim], 50 (1911), No. S, pp. 261-288; abs. in Bat. Centhl., 119 

 (1912), No. 20, pp. Jt88, ^89; Ztschr. Bot., 4 (1912), No. 6, p. 450).— The author 

 reports as the results of his experiments that various anilin solutions are taken 

 up by living parenchyma cells near the vascular bundles and stored and 

 strongly held by such cells, this being conspicuously true in case of epidermal 

 cells of leaves and flowers. The cells in question exhibited a selective i)ower 

 when provided with different colored solutions. The coloring matter once 

 admitted is not washed out if immersed for some time in standing or running 

 water. Thus, several acid coloring matters have now a claim to be considered 

 as vitally colorative, a character heretofore generally considered to be limited 

 to basic colors. Only a very few colloidal substances are foimd to possess this 

 ability. Transpiration favors greatly the entrance of coloring matters into the 

 cells. 



The significance of respiration pigments in the oxidation processes of 

 plants, "W. Palladin (Ztschr. (lannifjsphysiol., 1 (1912). ^'o. 2, pp. 91-105). — 

 Continuing previous work (E. S. R.. 27, p. 426). the author gives the final results 

 of his studies on the relation of respii-ation pigments to oxidation processes, in 

 substance as follows : 



The role of these pigments in the oxidation processes consists in the with- 

 drawal of hydrogen from the oxidizing substance. The oxidases appears as 

 ferments, building both water and pigment. During respiration the entire 

 hydrogen of the glucose, which is anaerobically broken up, is oxidized to water. 

 The oxidation of glucose by the aid of a respiratory pigment occurs with the 

 participation of water. Such oxidation occurs partly by use of the oxygen in 

 the glucose, partly by employment of that in the water assimilated, water being 

 both produced and assimilated during this process. The respiration pigments 

 are held to be necessary to the intracellular respiration and to the oxidation 

 of the hydrogen. The "chemical reactions held to support these statements are 

 given in some detail. 



Distribution of pigment in the seed coat of the cowpea, A. Mann (Ahft. in 

 Science, n. net:, 85 (1912), No. 913, p. lOO't). — A study of the seed coat of the 

 cowpea showed that it is composed of 3 principal layers of cells, an outer pali- 

 sade layer, a heavy-walled layer of empty cells below this, and a layer of con- 

 siderably compressed cells with a long axis parallel to the surface of the 

 cowpea. 



It was found that the colorations in the cowpea are the result of pigments de- 

 posited in 2 of these layers. In all colored cowpeas there is in the lowest layer a 

 basal color or practically uniform tint, which is a melanin compound of an 

 orange-yellow tint, grading into lemon yellow and pale buff. All the other 

 colors are obtained by superposing upon this basal color layer various pigments, 

 and these are uniformly deposited in the palisade cells. The 3 colors found in 

 the palisade cells are black or blue-black, sometimes purple, which is an antho- 

 cyanin, a yellow or a brown pigment, and an intensely black pigment, the last 

 2 being melanin compounds. By various arrangements of these superposed 

 tints, or by the absence of any pigments in these cells, the various schemes of 

 coloration in the cowpea are obtained. 



In the case of cowpeas having white or colorless seed coats, the result, it is 

 stated, is obtained by the suppression of all pigments, both in the basal color 

 layer and in the palisade color layer. 



A wild cowpea secured from Africa showed the same elements of color as 

 well as the schemes of coloration. 



The distribution of oxidases in plants and their role in the formation of 

 pigments, F. Keeble and E. P. Armstkoxg (Proc. Roy. Soc. [London], Ser. B, 



