BOTANY. 443 



assimilated from the air. In the molding of the Zhelanni oats, with a higher nitro- 

 gen content, u decrease was noted in tin' total nitrogen. Tn general, the total nitro- 

 gen of the albuminoid substances decreased during the period of molding. At first 

 the P. glaucum, growing on the Hungarian oats, resulted in a considerable increase 

 in albuminoids, but after' about 2 weeks this form of nitrogen diminished and the 

 nitrogen of the amido acids and that precipitated by phosphotungstic acid increased. 

 The nitrogen present in alcoholic extracts was found to increase during the entire 

 period of moldy growth. This is held to be of great importance, as in these- extracts 

 are present poisonous substances possessing some of the properties of plant alkaloids. 



In the second series of experiments Aspergillus niger was grown on flour obtained 

 from carrots, turnips, and potatoes. An increase in the total nitrogen was noticed in 

 the case of the carrots and turnips, but not of the potatoes. A considerable increase 

 of albuminoids took place at the expense of the nitrogen of the amido acids and that 

 precipitated by the phosphotungstic acid, the maximum taking place in about 12 

 days, after which the albuminoids were destroyed and the other nitrogenous com- 

 pounds augmented. The alcoholic extract from molded tubers gradually decreased. 

 The artificial addition of glucose and starch to molding tubers would not affect the 

 total nitrogen. 



The author undertook the study of the products of decomposition, and found 

 among the decomposition products of albuminoids under the development of .1. nigt r 

 on the seeds of yellow lupines an inconsiderable quantity of tyrosin and larger quan- 

 tities of leucin ami ammonia, the latter combined with oxalic acid. Tests for arginin 

 and histidin gave negative results. — v. fireman. 



Notes on the mycorrhiza of forest trees and their symbiosis with roots, 

 (i. F. C. Saradw I Rev. Mycol., ..'■'> i t90B . Yo. WO, pp. 157-172; 26 i 1904), No. 101, 

 pp. 1-19, pi. 1: abs. in Bot. < 'entbl, 95 (1904), Nos. 6-7, pp. 159, 160; 20,pp. 589,540).— 

 In continuation of a previous paper (F. S. II., 4, p. 693), the author summarizes his 

 investigations anil incorporates some recent information regarding the occurrence and 

 function of mycorrhiza on the roots of forest trees and shrubs. 



Forest trees are divided into 3 categories based upon the nature of their mycor- 

 rhiza — those having intracellular mycelium, such as cedrus, box, elms, and maples; 

 intercellular mycelium, and an external mycelial sheath, as spruce, fir, larch, pines, 

 oaks, hazels, birches, willows, and possibly linden; and those having neither inter- 

 nal nor external mycelium, as the ash, horse-chestnut, elder, etc. The common juni- 

 per is said to have an intracellular mycelium in the second group, but is without the 

 mycelial sheath. 



In the second part of the contribution the author gives a report on the biological 

 importance of mycorrhiza and a study of the biology of the fungus symbiont. The 

 opinions of Frank ami others regarding the importance of mycorrhiza are reviewed, 

 and it is claimed that Frank's experiments with forest seed in sterilized soil lacked 

 some important factors of control. The present author holds that humus in the soil 

 is necessary only in determining the abundance of mycorrhiza, and cites the infre- 

 quence of such growths in garden soils often rich in humus, while mycorrhiza may 

 lie and.often is abundant in trees growing in shifting sands. 



The presence of mycorrhiza in very sandy soils is said to be due to dead leaves 

 which carry the different fungi capable of infecting tree roots. The question of 

 nitrogen absorption through the mycorrhiza and roots tin- author claims has not 

 been proved. It is claimed that trees have become accustomed to symbiosis with 

 fungi, but it is held to be neither necessary nor advantageous to them. The infec- 

 tion takes place through vegetable debris carrying the fungi and the fungi live a sort 

 of saprophytic life in the soil. From a limited study of the various organisms, the 

 author claims to have recognized conidial types corresponding to Cladosporium and 

 Helminthosporium, and he believes that the fungi which produce mycorrhiza belong 



