AGKICULTUEAL BOTANY. 133 



enzym. Where the source of carbon was 10 per cent sugar supplemented by tan- 

 nic acid in variable quantities, it was found that the greater the eoucentratiou 

 of the tannic acid present the greater was the quantity of the enzym produced. 

 The greatest amount of tanuase was formed where tannic acid was the sole 

 source of carbon. 



Microchemical study of hydrocyanic acid in Prunus laurocerasus, K. Peche 

 {Hitzher. K. Akad. Wiss. [Vienna], Math. Naturw. Kl., 121 {1912), I, No. IS, 

 PI). 33-55, 1)1. 1, Jiy. 1). — The author gives the results of investigations on cherry 

 laurel. 



It is stated that hydrocyanic acid was clearly localized in leaf parenchyma, 

 and that a connection with previous illumination was established. Its location 

 suggests that it may have its origin in connection with the chlorophyll bodies of 

 the palisade cells, where it was found in close relation with cells containing 

 tannic acid. It was found also in other parts and some knowledge was gained 

 as to its movements and compounds in the plant. 



A brief bibliography is appended. 



The assimilation of free nitrog'en by Azolla, A. Oes {Ztschr. Bot., 5 {1913), 

 No. 3, pp. lJf5-16S, fig. 1). — The author reports concerning a study of Azolla in 

 various nutritive media since 1909, stating that this plant thrives very well in 

 media containing no supply of nitrogen ; that in this case a decrease in per- 

 centage of nitrogen in the dry substance is noted, although there is an absolute 

 increase of nitrogen; and that Azolla is able to appropriate free nitrogen from 

 the atmosphere, apparently by means of a blue-green alga (Anabieua), living in 

 symbiosis with it. 



The synthesis of amids which depends on ammonia absorbed throug'h the 

 roots, D. Peianichnikov {Rev. Gen. Dot., 25 {1913), No. 289, pp. 5-13). — A 

 study has been made of a number of kinds of plants to determine the possibility 

 of their utilizing dilute solutions of ammonium salts and transforming the nitro- 

 gen into other compounds. 



It was found that those plants which readily absorb ammonium chlorid or 

 ammonium sulphate, such as barley, maize, and pumpkius, form asparagin, or 

 glutamin, from the nitrogen obtained. Others, such as peas, which do not 

 absorb ammonium salts so readily or which require the addition of calcium car- 

 bonate to produce a rapid assimilation of ammonia, are able to form asparagin. 

 Lupines are unable to make use of ammonium salts for the synthesis of other 

 nitrogenous material, even with the addition of calcium carbonate. 



Observations on a fungus living on fatty hydrocarbons, G. Gola {Bui. 8oc. 

 Bot. Ital., 1912, No. 8, pp. 224-227). — This is a preliminary report of a study on 

 the behavior of fungi which are able to live on fatty hydrocarbons. 



It is said that the development of the fungi was most favox'able on purilied 

 vaseline, but much less so on liquid hydrocarbons. Some results seemed to 

 favor the hypothesis of a secretion by the fungus preceding the process of ab- 

 sorption, but other considerations suggested caution pending further investiga- 

 tions. 



Preliminary report on the relation of bacteria, yeasts, and mold fungi 

 to iodin compounds, A. Kossowicz and W. Loew {Ztschr. Odrungsphysiol., 2 

 {1913), No. 3, p. 158). — It is stated that no iodin was separated from potassium 

 iodid during experiments with several yeasts, or with most of the mold fungi 

 investigated. Aspergillus niger and Pcnic-illium glaucum separated considerable 

 iodin. as did also several bacteria examined, and Cladosporium herharum after 

 a time. 



Studies of osmotic pressure, M. A. Brannon {Abs. in Science, n. ser., 31 

 (1913), No. 9Jf9, p. 379). — An account is given of studies on osmotic pressure 

 made by cryoscopic methods, the Beckmann apparatus being employed to deter- 



