722 EXPERIMENT STATION RECORD. 



10, p. 235) Lutz has ivportod Ihiil maize, cucurliils. etc.. wcro al)l(' to utilizu 

 amins. directly assimilating tiiem. 



The author's experiments were conducted with ladislies so grown in tubes 

 as to i)revent the presence of niicro-organisms. In one series of experiments 

 the plants were supplied with a solution containing all the elements necessary 

 for their nutrition except nitrogen; in a second series calcium nitrate was 

 supplied in addition to the nutrient solution; while the other series contained 

 either ammonium chlorid or the hydi'ochlorids of methylamin. dimethylamin, 

 ethylauiin, and propylaniin. Parallel experiments were carried out employing 

 solutions containing 5 per cent glucose. 



It appears from the results of these investigations that the plants increased 

 considerably in weight when treated with calcium nitrate or ammonium chlorid. 

 The amins. however, showed a distinctly inhibitory inllnence on their growth. 



Physiological function of hydrocyanic acid in Sorghum vulgare, C. 

 Ravenna and M. Zamorani {Atti R. Accad. Lincei, Rend. VI. Sci. Fis., Mat. e 

 Nat., 5. ser., 18 {1909), II, No. 8, pp. 283-287; abs. m Jour. Chem. Soc. [London], 

 96 (1909), No. 566, II, p. 10^8). — A study was made of the origin of the protein 

 in plants, and the authors consider that the nitrogen is transformed from 

 nitrates to proteins through hydrocyanic acid .and amino compounds. In sup- 

 port of this view experiments with plants of S. vulgare to which asparagiu 

 was given as a nitrogenous food constituent showed that these plants contained 

 considerably less hydrocyanic acid than those to which no asparagin was sup- 

 plied. The asparagin was considered to have been utilized by the plants, as 

 otherwise they could not have developed for as long a iteriod as 30 to 35 days 

 on the reserve nitrates alone. 



Bemarks on the immunity of plants, N. Bernard (Bui. Inst. Pasteur, 7 

 (1909), No. 9, pp. 369-386, figs. 7; ahs. in Bot. Centhh, 111 (1909), No. 18, 

 pp. J/S-i, Ji55). — In previous papers (E. S. R., 22, p. 133). the author has dis- 

 cussed symbiosis as found in the orchids, while in this article an attempt is 

 made to generalize the facts heretofore discovered. In explaining the observa- 

 tions of other investigators on the reaction of plant cells in the presence of 

 fungus or animal parasites, he considers the Rhizoctonia and the orchids as 

 two antagonists, developing their means of attack and defense. The resulting 

 symbiosis represents the immunity realized by the invading fungus on the one 

 hand and the preservation of the essential tissues of the host on the other. 



The doctrine of symbiosis. I, The death of oak seedlings due to mycor- 

 rhiza, G. A. Nadson (Zhur. Bolyezni Rast., 2 (1908), pp. 26-1,0+XI, XII, figs. 4; 

 ahs. in CentU. Bakt. [etc.], 2. Abt., 26 (1910), No. 1,-5, pp. 100, 101).— In certain 

 Russian provinces a large number of one and two year-old oak seedlings were 

 found to be dying. An examination of the rootlets showed that the mycorrhiza 

 fungi, having been unfavorably influeuced by external conditions, formed an 

 abnormal growth of hyphfe, which among other things became very much en- 

 larged and, penetrating into the rootlets of the oak seedlings, killed them. It 

 is claimed that in this case a mycorrhiza fungus has acted as a parasite and, 

 therefore, that ectotropic mycorrhiza is really only another form of jiarasitism. 



The spread of the pine mistletoe in Tyrol and the significance of its dif- 

 ferent varieties, K. von Tubeuf (Naturw. Ztsclir. Forst n. Landw., 8 (1910), 

 No. 1, pp. 12-39, figs. Z6).— The introduction and spread of the pine mistletoe 

 In Tyrol is claimed to be due to the migratoi-y thrushes distributing the seed 

 during their spring migration northward and not to any of the winter thrushes 

 or other birds that winter over in Tyi'ol. Successful infection experiments with 

 the mistletoe are recorded for the following trees, namely, Pinus montana, 

 P. laricio, various species of larches, Cedrus atlantica, and other conifers. 



