AGRICULTURAL BOTANY. 421 



For this purpose a nitrogen-fi'ee medium was prepared and inoculated with 

 pure cultures of B. radicicola obtained from some 15 different siiecies of legumi- 

 nous plants. In liquid cultures the liquid became turbid after the second day 

 and cloudy within 30 hours. An increased growth of the organisms was noted 

 for about 2 weeks, and at the end of a month samples were taken from each 

 flask and tested for total nitrogen by the modified Kjeldah! method. The 

 amount of nitrogen present in the various cultures varied from 17 to 34 mg. of 

 nitrogen in 100 cc. of media. 



Pot , experiments with sand inoculated and watered with a nitrogen-free 

 medium were carried on, comparisons being made with similar pots watered 

 with water without any nutrient material. At the end of 6 weeks samples 

 were taken from the different pots and analyzed for total nitrogen. The results 

 obtained corresponded with those obtained in the liquid cultures. The author 

 believes that these pot experiments give a i-easonable basis for the assumption 

 that the inoculation of soils with bacteria from legume nodules will increase 

 the content of nitrogen in soils even if no legumes are present. Without the 

 presence of carbohydrates in the culture medium no nitrogen was assimilated. 



After the analyses were completed the pots were removed to the greenhouse, 

 planted with buckwheat, and moistened each day with distilled water. The 

 seed germinated well, and for 2 weeks but little difference could be seen in the 

 growth of the plants, but at the end of the third week the plants in the uninocu- 

 lated pots began to wilt while those in the inoculated ones continued to grow. 



The fixation of nitrogen by means of Bacillus radicicola w^ithout the pres- 

 ence of a legume, E. B. Fred and W. B. Ellett {PUmt World, 12 (1909), No. 6, 

 pp. 131-133, fig. 1). — Noted above from another source. 



Nitrogen assimilation of Sterigmatocystis nigra and the effect of chemical 

 stimulation, Marion E. Latham (Bui. Torrcy Bot. Cluh, 36 (1909), No. 5, pp, 

 235-2.'i-'f). — The present paper is offered as a contribution to the knowledge of 

 nitrogen metabolism of Sterigmafocystis (Aspergillus) nigra. In the experi- 

 ments plate cultures were made of the fungus and kept growing under sealed 

 bell jars in a nutrient medium to which zinc sulphate was added, previous exper- 

 iments having shown that zinc sulphate had a stimulating effect on the growth 

 of the fungus. 



The nutrient medium contained nitrogen, and it was found that the fungus 

 grown normally fixes free nitrogen which is found to be in combination if 

 nitrogen compounds be supplied in favorable quantity. The amount of nitrogen 

 so combined decreases if the culture be subjected to stimulation. The decrease 

 is in al)solute quantity and in amount per gram of dry weight of crop produced, 

 the diminution being shown most markedly by the decrease in combined nitrogen 

 in the substratum, from which it api)ears that the niti'ogen may be used in 

 metabolism. The amount of nitrogen entering into the composition of the 

 mycelial felt I'emained relatively the same in normal and stimulated growths. 



The author states that the work may be considered as confirming that of 

 earlier investigators with normal cultures, and to have shown that while stimu- 

 lated crops behave more economically with regard to their carbohydrate con- 

 sumption, and while the amount of nitrogen entering into the composition of the 

 fungal felt is relatively the same as for normal growth, yet with regard to 

 nitrogen relations stimulated cultures are less thrifty than normal ones. It is 

 shfiwn that unless nitrogen be supplied in too great quantity the fungi are able 

 to use gaseous nitrogen and bring it into chemical combination even in excess 

 of actual needs. 



The accumulation of nitrates in parasitic and saprophytic plants, L. Lutz 

 (Bui. Soc. Bot. France, 55 (1908), No. 2, pp. 10.'f-109). — The presence of nitrates 



