324 EXPERIMENT STATION EECORD. 



by the oxidase and forms a lanuin or tannin-liko body having Ihe property of pre- 

 cipitating proteid matter, and at the same time forming a germicidal fluid. 

 This oxidase acts only in an acid solution, and when present in an amount 

 above a certain undetermined minimum. The above conditions are always present 

 in normal immature pomaceous fruits. When normal, immature fruits are 

 subjected to injury by fungi, insects, or mechanical agencies, the action of the 

 oxidase on poly-atomie phenol is brought aliont with the effccis as stated above." 



Some properties characteristic of amylose and amylopectin, Mme. Z. 

 Gruzlwska {Compt. Rend. Acad. Set. [Paris], 152 {19Jl),No. 12,pp.785-7SS).— 

 A study has been made of potato starch, and by means of a method described 

 the author states that the starch grain can be easily separated into two dis- 

 tinct bodies, amylose and amylopectin. Amylopectin and mineral matter com- 

 pose the envelope of the starch grain, while amylose is localized in the interior. 

 Amj-Iose, like inulin and some other bodies, has the property, upon becoming 

 old, or under the action of cold, of precipitating from its solutions. This 

 phenomenon has been called retrogradation. Purified amylopectin is not pre- 

 cipitated from its solutions either upon standing or under the influence of cold. 



On the formation of anthocyanin, Miss M. Whedlale (Jour. Genetics, 1 

 {1911), Xo. 2, pp. 133-15S). — The author has made a study of anthocyanin to 

 determine the chemical processes which underlie its formation. 



On summarizing her results it is said that the soluble pigments of flowering 

 plants, collectively termed anthocyanin, are oxidation products of colorless 

 chromogens of an aromatic nature which are present in the living tissues in 

 combination with sugar as glucosids. The formation of the glucosid from 

 chromogen and sugar is in the nature of a reversible enzym action. The 

 chromogeu can be oxidized to anthocyanin only after liberation from the 

 glucosid, and the process of oxidation is carried out by one or more oxidizing 

 enzyms. The amount of free chromogen, and hence the quantity of pigment 

 formed at any time, is inversely proportional to the concentration of sugar and 

 directly proportional to the concentration of glucosid in the tissue. The local 

 formation of anthocyanin which is characteristic of the normal plant is due to 

 local variation in concentration of either the free sugars or the glucosids in 

 the tissues in which the pigment appears. The abnormal formation of pig- 

 ment is attributed to differences in the concentration of these same substances 

 due to changes in metabolism. 



The application of the hypothesis relating to anthocyanin to Mendelian 

 factors is discussed. 



The absorption of colloidal organic material, P. Maz£; (Compt. Rend. 

 Acad. Sci. [Paris], 152 (1911), No. 12, pp. 783-785).— Studies were made with 

 maize grown in cultures to which starch, peptone, and humus compounds were 

 added in connection with salts of ammonia. The absorption of the colloidal 

 organic matter, as well as its assimilation, was demonstrated. Under the in- 

 fluence of the products of excretion a neutral solution containing humus was 

 acidified, while in another series the solution remained neutral on account of 

 the liberation of soda. 



The starch did not present any trace of liquefaction or sacchariflcation, nor 

 did it show the presence of amylase. Preliminary investigations indicated that 

 sucrase in the solutions gave negative results. The roots did not excrete either 

 amylase or sucrase, contrary to common belief. The sacchariflcation of starch 

 and the inversion of saccharose was brought about at length under the in- 

 fluence of the progressive acidification of the nutrient solutions. 



The action of some hydrolyzable salts and colloids on plants, A. GRfiooiRE 

 (Bui. Soc. Chim. Belg., 25 (1911), No. 2, pp. 85-103). — In a previous publication 

 (E. S. R., 23, p. 527), the author showed that certain readily hydrolyzable salts 



