730 EXPERIMENT STATION EECOSD. 



effect of citric acid absorbed by the seeds of tomato, pepper, maize, etc. In the 

 preseut paper an account is given of investigations with beans and peanuts to 

 determine the effect of citric acid and glucose solutions on the respiration of 

 the seed. 



It was found that the presence of these substances in a liquid medium where 

 germinating seeds have begun to swell modifies the respiratory quotient, some- 

 times increasing and other times diminishing it, according to the variety of the 

 seed and to the substance used. When the substance was acid there was always 

 an increase, but when glucose was added there was an increase with some seeds, 

 such as the bean, and a diminution with others, as was the case with the peanut. 



Tannin in the seed coats of barley, A. Reichard {Ztschr. Chem. u. Indus. 

 KoUoide, 10 (1912), No. 5, pp. 21-^-219; ahs. in Jour. Chem. Soe. [London^, 102 

 {1912), No. 596, II, pp. 592, 593). —In a previous publication Brown (E. S. R., 

 21, p. 126) showed that a membrane in the testa of the barley grain exerts a 

 selective action on dissolved substances, inasmuch as only certain of them can 

 pass through it into the seed. The present author has carried on a series of 

 investigations and has found that there is a liind of tannin in the seed covering 

 of barley and that there is an undoubted parallelism between the power of a 

 substance to dissolve this material and its ability to penetrate the membrane. 



The investigations were made by a variety of methods, which included the 

 direct action of different substances on sections of the barley grain with subse- 

 quent examination of the membrane for tannin, and also adding various sub- 

 stances to ordinary tannin in a test tube and observing the effects. There 

 appears to be some evidence that the tannin in barley is associated with a 

 proteid, and the action of different substances on a compound of protein and 

 tannin was investigated. 



The author ascribes the resalts obtained to a solvent action on the tannin, 

 thus permitting diffusion, or in some cases to a coagulating effect of the reagents 

 on the tannin complex, which prevents diffusion. 



Pentosans and methylpentosans in seeds of Glycine hispida and Phaseolus 

 vulgaris during g'ermination, K. Miyake (Jour. Col. A.gr. Tohoku Imp. Univ., 

 .'f (1912), No. 8, pp. 327-335). — From a study of germinating bean seeds the 

 author concludes that pentosans and methylpentosans are not ordinarily used 

 as reserve or nutrient material in germination, being utilized rather to form 

 skeletal structures, but that in case of exhaustion of the more readily available 

 materials these carbohydrates are made to supply the usual offices of such sub- 

 stances, methylpentosans in the larger quantity of the two. 



The artificial nourishment of seedlings, W. Zaleski and N. Tutorski 

 (Biochem. Ztschr., J,3 (1912). No. 1-2, pp. 7-,9).— The authors experimented with 

 the axial parts of newly sprouted peas, sterilized and kept in darkness for 20 

 days in Knop's solution with addition of carbohydrates or in Knop's solution 

 with a small amount of calcium sulphate to which was added either a nitrate, 

 ammonium phosi>hate, asparagin, or crushed cotyledons of peas. 



In carbohydrates these stems showed remarkable increase in size and dry 

 weight, saccharose taking the most and galactose the least part in building 

 new material. Nitrates, ammonia, and asparagin all gave considerable in- 

 crease in nitrogenous materials, but their utilization is claimed to be indirect, 

 the nitrates being first reduced an4 the nitrogen built into ammonia, later 

 forming amino acids. Asparagin is thought to act in some small part directly 

 in the formation of new nitrogen compoundt'. Ammonia is not thought to be 

 directly elaborated into nitrogen products. 



Investigations on the nourishment of seedlings with amino acids are still in 

 progress. 



