9(30 EXPERIMENT STATION RECORD. 



introduction of nutritive solutions of varying concentration, while giving positive 

 results, were not found as efficient as dry salts.— p. fireman. 



Investigations on the starch and fat content of fir trees, L. Fabricius 

 (Naturw. Ztschr. Land u. Forstw., 3 (1905), 'No. 4, pp- 137-176, pis. 2).— Investiga- 

 ting arc reported on the fluctuation of the reserve materials in the fir tree at differ- 

 ent periods of the year. The trunks and roots of trees of various ages were 

 examined at eight different times during the year and their starch and fat content 

 determined. 



Physiological investigations on the reserve material of trees, Leclerc du 

 Sablon ( Rev. Gni. But., 18 {1906), Nos. 205, pp. 5-25, figs. 7; 206, pp. 82-96, figs. 6).— 

 In a previous publication (E. S. Ii., 14, p. 1045) an account was given of observations 

 on the reserve carbohydrates in the leaves, stems, and roots of chestnut and other 

 deciduous trees at different times of the year. 



In the present memoir the investigations are extended to include trees with per- 

 sistent foliage, and also to test the effect of decortication on the production and trans- 

 fer of carbohydrates. Among the evergreen trees studied were the holly oak, Aus- 

 trian pine, larch, and Japanese and European euonymus, and among the deciduous 

 trees, the pear, quince, etc. In addition to the carbohydrate reserves, observations 

 were made on other reserve materials, water contents, etc. 



In the case of trees with persistent foliage the synthesis of carbohydrates takes 

 place with varying degree throughout the year. The reserve supply is drawn upon 

 in the spring of the year wken the buds are unfolding and also during periods of 

 intense respiration. As a result the minimum of reserve material occurs during the 

 summer, from which time it increases throughout late summer and winter, attaining 

 the maximum just before the spring budding. With the deciduous species the car- 

 bohydrate assimilation takes place only during the summer season, or from April 

 to October, but during that period it is much more vigorous than in the case of 

 evergreens. 



The maximum of carbohydrate reserves in both stems and roots coincides with the 

 autumnal fall of the leaves. In the spring of the year when young shoots are being 

 put out rapidly the minimum of the reserve material is noted. The young shoots 

 seem to be largely formed from the stored reserves of the stems and roots, and the 

 abundance of the reserves determines the winter respiration of the tree, as well as 

 the extent of the new spring growth. In all the species studied an increase in the 

 water content of the trees was noticed just at the period of the beginning of growth 

 in the spring, and in general a maximum of carbohydrate reserve material and a 

 minimum of water are coincident. The water content is said to depend more upon 

 the state of growth than on the degree of soil humidity. 



Attention is called to the fact that the starch in the carbohydrate reserve material 

 diminishes during winter and shows an increase in the spring of the year, and in 

 general the maximum of carbohydrates is accompanied by a minimum of starch. 

 This is explained by the theory of the transformation of starch into reserve cellulose, 

 which is again changed to a starch or some similar body preparatory to use by the 

 tree. 



Contributions to the biology of Rhizobia. IV, Two coast Rhizobia of 

 Vancouver Island, B. C, A. Schneider (Bot. Gaz., 40 (1905), No. 2, pp. 135-139, 

 figs. 3). — The author describes the micro-organisms occurring in the tubercles found 

 on the roots of 2 species of leguminous plants, beach vetch and beach clover, com- 

 mon on Vancouver Island. These forms present quite different morphological 

 characters, and it is thought probable that there are extreme types which are derived 

 from an original form similar to, but not necessarily identical with, that occurring 

 on rassia, black locust, and other species of leguminous plants. 



Contributions to the biology of Rhizobia. V, The isolation and cultiva- 

 tion of Rhizobia in artificial media, A. Schneider (Bot. Gaz., 40 (1905), No. 4, 



