228 PHYSIOLOGY [Bot. Absts., Vol. IV, 



continued to cause the same changes throughout a 4-day incubation period at 45°. Increase 

 in the number of spores resulted in an increase in enzymic activity. The enzyme present 

 exhibited the characters of invertase. The spores of A. Syduwi contain a gum-forming enzyme 

 which parallels invertase activity. — The limit of concentration, when 100,000 to 400,000 mold 

 spores per cubic centimeter of sugar solution are used, is between 18 and 24 per cent actual 

 sucrose. — D. Reddick. 



1514. McGinty, R. A. Diastase activity in relation to stage of development and carbohy- 

 drate content of the tuber of Solanum tuberosum. Ann. Missouri Bot. Gard. 6: 223-251. 1919. 

 — Following a review of the literature on this subject there are reported results on experiments 

 (1) to determine diastase activity in tubers at various periods of development; (2) to estimate 

 the reducing sugars and sucrose by the method formulated by Davis, Daish, and Sawyer; 

 and (3) to estimate starch by means of taka diastase. Diastase activity and starch content 

 increase with the advance of tuber formation, while the sugar content decreases. Potato 

 juice preserved with toluol for 24 hours at room temperature showed a marked decrease in 

 diastatic activity. An activating agent which is not destroyed by boiling nor precipitated 

 by alcohol is coenzymic with the diastase of potato juice. — S. M. Zeller. 



1515. Northrop, J. H., L. H. Ashe, and R. R. Morgan. A fermentation process for the 

 production of acetone and ethyl alcohol. Jour. Indust. Eng. Chem. 11: 723-727. 1919. — A 

 commercial method for the manufacture of acetone and ethyl alcohol by means of a fermenta- 

 tion process of various sugars induced by a newly described organism, Bacillus acetoethylicum, 

 is discussed. — Henry Schmitz. 



1516. Onslow, Muriel Wheldale. Oxidizing enzymes. I. The nature of the "Perox- 

 ide" naturally associated with certain direct oxidizing systems in plants. Biochem. Jour. 13 : 

 1-9. 1919. — A relationship is shown between the browning of injured tissue of certain plants 

 and a direct oxidase reaction with guaiacum, likewise between those showing no browning and 

 the direct oxidase reaction (requiring the presence of hydrogen peroxide). It is argued from 

 experimental data that the direct oxidase reaction in tissues showing browning (such as pear 

 fruit or potato tuber), is due to the presence of a peroxidase and an aromatic catechol group. 

 On injury the peroxidase activates the oxidation of the aromatic with the formation of a per- 

 oxide, this system then bringing about the bluing of guaiacum. — The formation of the per- 

 oxidase-peroxide system can be prevented by the extraction of the aromatic, then reformation 

 may be effected by again introducing the aromatic. It is held that plants not showing brown- 

 ing of tissue do not contain the catechol group. — A. R. Davis. 



♦ 



1517. Pringsheim, Hans, and Adelheid Magnus-von Merkatz. Fermentversuche an 

 Zellulose abbauprodukten. [Fermentation experiments with certain products of cellulose dis- 

 integration.] Zeitschr. Physiol. Chem. 105: 173-178. 1919. — Pringsheim and Magnus-von 

 Merkatz point out the fact that dextrines from both starch and glycogen are split to maltose 

 by diastase. They raise the question whether diastase has a similar effect on cellulose dex- 

 trine. By using Madsen's acetylization method they gained cellulose dextrine from cotton 

 that was soluble in water and gave no osazone reaction. The dextrine thus obtained is 

 strongly reducing to Fehling's solution and is considered by the authors as the end dextrine 

 of cellulose. Diastase will not split cellulose dextrine. They also derived zellobiose by the 

 Madsen method. The contents of the first stomach of cattle, the intestine and the pancreas 

 bore no enzyme that would split zellobiose. They conclude that the splitting of this substance 

 in the alimentary canal of the cattle must be due to cellulose bacteria. — William Crocker. 



1518. Schmitz, Henry. Studies in the physiology of the fungi. VI. The relation of 

 bacteria to cellulose fermentation induced by fungi, with special reference to the decay of wood. 

 Ann. Missouri Bot. Gard. 6: 93-136. 1919. — Sawdust cultures, prepared from heart -wood of 

 Douglas fir, western hemlock, white ash, and red oak, were inoculated with pure and mixed 

 cultures of the following fungi and bacteria: Fumes pinicola, Lenzites saepiaria, Polystidus 

 versicolor, Bacillus vulgatus, B. vulgaris, B. coli, B. prodigiosan, Bacterium mycoides, and 



