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



Absts. 2, Entry 614).] Bot. Gaz. 67: 517. 1919. — The reviewer notes that "the author seems 

 to have overlooked most of the literature on the effect of illuminating gas on plants." — 

 II. C. Cowles. 



160S. Crossley, M. L. Gentian violet — Its selective bactericidal action. Jour. Amer. 

 Chem. Soc. 41:2083-2090. 1919. 



1609. Duggar, B. M., and Anne W. Davis. Seed disinfection for pure culture work: the 

 use of hypochlorites. Ann. Missouri Bot. Gard. 6: 159-170. 1919. — Seeds were treated both 

 continuously and discontinuously, with commercial chloride of lime, Javel water, sodium 

 hypochlorite, and Dakin's soluble chlorazene, for various intervals of treatment. After "tak- 

 ing into consideration both (1) the capacity of the seed for germination after treatment and 

 (2) the relative freedom from contamination," "chlorinated potassa," or Javel water, is 

 recommended as the most satisfactory agent. The interval of treatment required for certain 

 seed is 3 hours or more with concentrations of 10 to 20 per cent. Intermittent disinfection is 

 fully warranted in some cases, but the value of soaking the seed before long period treatment is 

 questioned, although a preliminary washing of all seed is advisable. — S. M. Zeller. 



1610. McH argue, J. S. The effect of manganese on the growth of wheat; a source of 

 manganese for agricultural purposes. Jour. Indust. Eng. Chem. 11: 332-353. 1919. — Man- 

 ganese in suitable dilution stimulates the growth of wheat, increases the size and nitrogen 

 content of the grain, and evidently performs an important function in the normal growth and 

 development of the plant. — H. Schmitz. 



1611. Steinberg, Robert Aaron. A study of some factors in the chemical stimulation of 

 the growth of Aspergillus niger. Amer. Jour. Bot. 6: 330-372. Fig. 1-2. 1919. — Aspergillus 

 niger was grown in flasks in Pfeffer's solution, which was modified by changing its acidity, or 

 altering the concentration of the components; or purified by autoclaving with calcium carbon- 

 ate to remove traces of iron and zinc. The dry weight of mycelium produced in seven days is 

 taken as the yield. Increased acidity of the solution produces an increase in yield and a de- 

 crease in the amount of sporulation, — effects similar to those observed upon adding salts of 

 heavy metals, especially iron and zinc. Since the stimulating salts all undergo partial hy- 

 drolysis in water, thereby increasing the acidity of the solution, it is possible that the phenome- 

 non is the same in both cases. In purified Pfeffer's solution, practically no growth occurs; 

 slight stimulation results from the addition of either iron or zinc, but both must be present to 

 produce the maximum effect. Stimulation formerly thought to be due to zinc alone is doubtless, 

 the effect of both zinc and iron, the latter having been present as an impurity. — G. S. Torrey. 



1612. Steinkoenig, L. A. Relation of fluorine in soils, plants, and animals. Jour. 

 Indust. Eng. Chem. 11: 463-465. 1919— See Bot. Absts. 4, Entries 1636, 2716. 



1613. Wehmer, C. Leuchtgaswirkung auf Pflanzen. [Effect of illuminating gas on 

 plants.] Ber. Deutsch. Bot. Ges. 36: 460-464. 1918. — If the roots of young trees are exposed 

 to the gas in late fall, the injury resulting manifests itself in the loss of the foliage of the 

 tree. Later exposures show no direct effect. However, the following spring the treated trees 

 die. The poisoning principle of the gas is hydrogen cyanide which is always present in small 

 quantities. Whenever the HCN was removed by passing the gas through suitable wash 

 bottles, no injury resulted, or the effect was markedly decreased. — Ernst Artschivager. 



1614. Wyeth, F. J. S. The effects of acids, alkalies, and sugars on the growth and indole 

 formation of Bacillus coli. Biochem. Jour. 13: 10-24. 1919. — Bacillus coli was grown on 2 

 per cent peptone media, the optimum H-ion concentration of which was found to lie between 

 P H 4.27 and 9.87. A change in the initial reaction results in a change in the same direction 

 but of less magnitude in the final reaction of the culture. Data on these changes are given. 

 It is noted the formation of indole is retarded by free alkali or acid, — likewise certain sugars 

 cause the same effect by inhibiting the activity of the proteolytic enzymes. Thus 2 per cent 

 glucose to peptone media completely inhibits indole formation, 2 per cent lactose or maltose 



