194 PHYSIOLOGY [BoT. Absts., Vol. VII, 



1301. Fisher, Hugo. Pflanzenwuchs und Kohlensaure. [Plant growth and carbonic 

 acid.] Naturwissenschaften 8:413-417. 1920. — The fact that CO2 may be present in mini- 

 mum quantity and thus be the limiting factor in plant growth is first pointed out. Then 

 reference is made to the possibility that CO2 present in the air may be increased by the CO2 

 formed through the activity of the soil organisms. A review is given of his own and other 

 experiments where the amount of CO2 in the air is increased with resulting increase in growth 

 as well as flower and fruit production. A practical application on a large scale is noted 

 where the waste gases (containing about 5 per cent CO2) produced in a certain steel mill 

 were added to greenhouse and field cultures with favorable results. — Orton L. Clark. 



METABOLISM (GENERAL) 



1302. Anderson, R. J. Occurrence of inosite hexaphosphoric acid in the seed of the silver 

 maple (Acer saccharinum). Jour. Biol. Chem. 43:46&-475. 1920. — The principal organic 

 phosphorus compound of maple seed is identical with the inosite hexaphosphoric acid which 

 has been isolated from other plant material. Freshly powdered maple seed apparently do not 

 contain any active phytase. — G. B. Rigg. 



1303. Anonymous. Coloring matters of plants. Nature 105: 1*39-140. 1920. — A popular 

 summary regarding nature and distribution of such pigments. — 0. A. Stevens. 



1304. BoRNEMANN. Die organische Ernahrung bei hoheren griinen Pfianzen. [Organic 

 nutrition of higher green plants.] Naturwissenschaften 8:496-497. 1920. — This corrects a 

 statement by Czapek in an article of the above title appearing in Heft 12, 1920, of this jour- 

 nal to the effect that the CO2 from the soil does not have an influence on plant growth. The 

 original quotation from Molliard is given, in which he states that CO2 from soil organisms 

 does have an appreciable effect on plant growth, which Czapek incorrectly translated. — 

 Orton L. Clark. 



1305. BoTTOMLEY, W. B. The effect of organic matter on the growth of various water 

 plants in culture solution. Ann. Bot. 34: 353-364. 1920. — To determine the necessity of 

 organic matter for the growth of water plants in particular, and all plants in general, plants 

 of Lemna major collected in May were grown in 150 cc. quantities of the following solutions: 

 (1) Detmer's solution; (2) nucleic acid from raw peat, 1 gm. to 500 cc. water; (3) autoclaved 

 Azotobacter 1 gm. to 1000 cc. water; and (4) water extract of bacterized peat, 1 gm. to 500 cc. 

 water. One hundred freshly collected plants averaged 24.8 mg. in weight. After 3 weeks, 

 (1) averaged 20.4 mg. ; (2) 44.8 mg.; (3) 47.2 mg.; and (4) 46.5 mg. With (1) and (4) Lemna 

 major collected in July, also Salvinia natans, Azolla fliculoides, and Limnobium stoloniferum 

 showed similar results. The amount of organic substances in the medium was only 184 parts 

 per million as compared to 5500 parts for nutrient salts; hence organic substances are not of 

 nutrient value, but enable the plants to make full use of the nutrient salts. These results in 

 conjunction with earlier ones indicate the necessity of a small quantity of organic substance 

 for normal growth. — F. S. Wolpert. 



1306. Carey, Cornelia Lee. A method of preparation and some properties of a starch gel. 

 Bull. Torrey Bot. Club 47: 455-463. 1920.— A starch gel was prepared by mixing 100 grams of 

 commercial corn starch with 150 cc. of distilled water, pouring into Petri dishes, and treating 

 in the autoclave for thirty minutes at from 105° to 110°C. When still warm the starch was 

 cut into strips and dried. The properties of this gel, its adsorptive powers, and its micro- 

 scopic structure are discussed. — P. A. Munz. 



1307. Czapek, Friedrich. Die organische ErnShrung bei hoheren griinen Pfianzen. 

 [The organic nutrition of the higher green plants.] Naturwissenschaften 8: 226-231. 1920. — 

 A review is given of data concerning various organic substances found in the soil and their 

 absorption by the green plant. The carbon and nitrogen requirements of the higher plants, 

 also the methods of culture used in testing the value of organic compounds, are described 



