554 EXPERIMENT STATION RECORD. 



botanical j^anU-ns of Manila. NoteB on the work accomplisluMl since Anierican occu- 

 pation and a l)il)liofjrai)hy of the more essential books relating to the botanical work 

 in the Philippines are also fi;iven. 



A study of the distinguishing characteristics of oat varieties, Drporu and 

 Dassonvillk {Jicr. (iai. Hot., 15 {1903), No. 175, pp. i.'S!>-.109, figs. ,5).— The authors 

 have made a botanical study of color, awns, size, form, weight, proportion of seed to 

 chaff, size of pedicels, and the cicatrix at the base of the grain, as characters for the 

 differentiation of the numerous varieties of oats. They conclude that there is no one 

 character upon whitrh to base varietal differences, but that many varieties may be 

 distinguished by a combination of characters. 



The color of the grain is one character which is the most easily recognized and one 

 of the most important, but in using this character for the differentiation of si)ecies it 

 is necessary to consider the color of the grain in mass rather than that of individual 

 seed since slight variations are frequently noticed in individuals of the same variety. 



Descriptions are also given of the seed of a number of other species of Avena and 

 directions given for distinguishing them from those of ^1. sativa. 



The effect of gases and fumes upon cultivated plants, U. Brizi {Staz. Sper. 

 Agr. Ital, 36 {1903), No. 4-5, pp. 279-384, pis. 2, figs. -^).— Attentit)n is called to the 

 effect of gases and fumes from various industrial establishments, such as gas works, 

 chemical works, smelters, foundries, etc., in their bearings on croji production, as 

 well as the important legal aspect of the subject. A review and summary is given 

 of considerable literature relating to the subject, and the author gives the results of 

 his observations and experiments along this line. 



The effect of sulphur dioxid, sulphurous and sulphuric acids, hydrochloric acid, 

 fumes of various minerals, such as arsenic, zinc, mercury, etc., the vapors arising 

 from the manufacture of superphosphates and sulphuric acid, nitric fumes, coal 

 smoke, illuminating gas, etc., upon a large number of economic plants is shown, and 

 experiments are reported which were conducted to discover, if possible, some means 

 of preventing or moderating the injurious effects i)roduced by these agents. Many 

 of the gases, especially the sulphurous and hydrochloric acids, rapidly plasmolyze the 

 cell contents of the plant, causing a discoloration that is often mistaken for a fungus 

 attack, and finally result in the disorganization of the chloroplastids. Coal smoke 

 was found to be injurious princiimlly from the mechanical effect of its deposition on 

 foliage, although the gases often had an important effect on the plants. A bibli- 

 ography of more than 100 titles completes the paper. 



Influence of medium on the acids of plants, E. Charabot and A. Hebert 

 {Compi. Rend. Acad. Sci. Pari.'t, 136 (1903), No. 17, pp. 1009-1011). —Alter briefly 

 summarizing previous investigations regarding the formation of ethers, alcohols, and 

 acids in plants, an account is given of the author's investigations on the influence of 

 the medium in which plants are grown on the volatile acids which they contain. At 

 the same time the variation in the alkalinity of the ash of the plants was studied. 



The experiments were made on peppermint cultivated in soils to which different 

 mineral salts were added, and the results compared with check plants grown in the 

 standard soil. The quantity of volatile acids was determined in leaves from different 

 parts of the plant and the averages taken. 



In general it was found that mineral salts added to the soil increased the amounl 

 of volatile acid in the fresh leaves, but this difference seemed to be apparently due to 

 differences in the hydration of the plants. It was less noticeable when compared 

 with the dry weight of the leaves. It was found that the chlorids and sulphates 

 slightly increased the proportion of volatile acid to dry weight of the leaf, the nitrates 

 reducing it slightly, while disodium phosphate increased the proportion very 

 materially. Tables are given showing the proportion of the volatile acids to the total 

 acid of the plants. The salts which favor the reduction of water in the plants tended 

 to increase the proportion of volatile acids to the total acids. 



