AGRICULTURAL BOTANY. 429 



Investigations were made of the clianges produced by tlie action of hydro- 

 cliloric acid and formalin on tannin, and it was sliown tliat these substances 

 readily changed the color of the solution to red or reddish violet. It is claimed 

 that tannins are widely distributed in plants and that from them, through the 

 action of diastase, red coloring matters of a tannoid nature are formed. 



The respiration of plants, F. Czapek (Ergcb. PInj.sioL, 9 {1910), pp. o67~ 

 613). — This is a critical review of some of the more impoi-tant literature relat- 

 ing to the respiration of plants, the author setting forth the various theories 

 and opinions regarding this vital function. A bibliography of more than 100 

 publications is given. 



The formation of ammonia in plant tissues deprived of oxygen, M. Mol- 

 LiARD {Bill. Soc. Bot. Fiance, 56 {1909), Xo. 6, pp. 332-33-i ; abs. in Bot. Centbl., 

 113 {1910), No. 10, p. 254)' — 111 the course of investigations on the alcoholic 

 fermentation of plant tissues in aseptic media, the author observed, while work- 

 ing with fragments of squashes, that as the liberation of carbon dioxid grad- 

 ually ceased a certain amount of the gas disappeared, seeming to be fixed as a 

 base in the tissues of the plants. The change of the reaction in these tissues 

 together with the positive results furnished by the use of Nessler's reagent 

 showed that there was a production of ammonia during the experiment. 



The formation of ammonia is attributed to the presence of a diastase which had 

 been previously formed in the squash and had remained active for a long time. 

 This phenomenon is believed to be compai'able to that observed in cultures of 

 different species of Fusarium, where under certain conditions a red pigment is 

 developed which colors the mycelium, passing into a blue coloration when the 

 reaction of the liquid changes and ammonia is formed. 



The ammoniacal fermentation observed in these two cases is believed to be a 

 process in the death of the plant tissues, and confirms the views of Pfliiger, who 

 has claimed that at the death of the cell the cyanogen radical of albuminoid ma- 

 terial in the plant is changed to an ammonia radical. 



On nitrogen fi.xation in soiis with cellulose as a source of energ'y, A. Koch 

 {Centbl. Bkl. [etc.], 2. AM., 27 {1910), No. 1-3, pp. i-7).— This is a continuation 

 of studies on the fixation of free nitrogen in the soil by certain micro-organisms 

 (E. S. R., 22, p. 428), in which the use of cellulose as a source of energy for the 

 nitrogen-fixing bacteria is being investigated. 



Vessels containing 400 gm. of soil to which 12 gm. of cellulose in the form of 

 pulped filter paper had been added were infected with cellulose bacteria from 

 four different sources, viz, ordinary soil, compost, stable manure, and sewer 

 slime, respectively. The experiments extended over a period of six months, 

 beginning with the first of August and terminating the first of the following 

 Fel>ruary, a soil moisture content of 25 per cent being uniformly maintained in 

 each vessel throughout the entire time. 



The soil infected with the stable manure bacteria showed a greater quantity 

 of fixed nitrogen and a smaller amount of cellulose present at the end of the 

 experiments than any of the other infected soils. The average amount of cellu- 

 lose consumed per vessel in each series during the experiment was as follows : 

 For earth infection 1.2 gm., compost 3.85 gm., stable manure 10.35 gm., and 

 sewer slime 1.85 gm. ; while the average amount of nitrogen present in each series 

 in milligrams per 100 gm. of dried soil was for earth infection 90.73, compost 

 92.0.5, stable manure 117.27, and sewer slime 87.15. The soil infected with stable 

 manure bacteria also gave a greater percentage of fixed nitrogen than a like 

 amount of soil to which 14.5 gm. of dextrose had been added. 



It is claimed as a result of these experiments that the beneficial effects obtained 

 by the addition of a small quantity of stable manure to any soil is due to the 

 introduction by this means into the soil of the proper kind of cellulose-fermenting 



