I02 BOTANICAL GAZETTE [January 



produces it, but is very toxic to plants belonging to a species in which the 

 glucoside is not naturally found. The toxic glucoside, when added to Knop's 

 culture medium in which the plants are grown, produces very marked abnormal 

 changes in the morphology of the roots, resulting also in a very stunted growth 

 of tops. It appears that we have here another group of substances, the indi- 

 viduals of which possess a constitution suf3ficiently characteristic of the species 

 in which they are found that when they are applied to individuals belonging 

 to nonrelated species they produce abnormal responses. The author has not 

 yet found that glucosides will furnish carbohydrate food for plants when they 

 are grown in a carbon dioxide free atmosphere, as has frequently been found 

 to be the case with glucose. 



Those wishing to germinate seeds and grow seedlings under aseptic condi- 

 tions will be interested in the detailed descriptions of the apparatus and pro- 

 cedures employed in growing his plants. An excellent review of the mass of 

 literature on the subject and a survey of glucosides in plants will be found in 

 the earlier papers of this series. — Charles O. Appleman. 



Physiology of fungi. — Duggar, Severy, and Schmitz'^ have undertaken 

 a study of the comparative nutrient value of some of the decoctions ordinarily 

 used in the preparation of culture media for fungi. The decoctions which were 

 prepared on the basis of 50 gm. of dry matter to a liter of water were made 

 from bean, sugar beet, prune, potato, turnip, cornmeal, apple, mangold, celery, 

 carrot, and salmon. The standard decoctions were employed alone and in 

 combination with sugar and various mineral nutrients. It was found that in 

 their nutrient value the decoctions are very dissimilar for different fungi. 

 The addition of sugar in most cases increases the yield, but the addition of sugar 

 with nitrate and phosphate gives a very much greater yield than the addition 

 of any of these substances alone. It is pointed out also that the standardiza- 

 tion of the decoctions on Fuller's scale leaves them differing widely in hydrogen 

 ion concentration. This work brings out the fact that little is really known of 

 the nutrient value of plant decoctions, which it appears are generally deficient 

 in nutrients and require the addition of considerable "fertilizer" to produce 

 the greatest growth of fungi. — H. Hasselbring. 



Maps of rainfall and crop plants. — Among the recent publications of the 

 United States Department of Agriculture there are two at least of decided 

 interest to ecologists and plant geographers. The first is a rainfall map of the 

 United States'" embodying the data from not less than 3600 stations. The 

 precipitation is given in inches and the map is in 8 shades of blue. An interest- 

 ing insert map gives the rainfall from April i to September 30, and exhibits a 



'* Duggar, B. M., Severy, J. W., and Schmitz, H., Studies in the physiology of 

 fungi. Ann. Mo. Bot. Gard. 4:165-173; 279-288. 1917. 



'' KiNX'ER, Joseph B., Atlas of American agriculture. Advance sheet i : Precipi- 

 tation. U.S. Dept. Agric. Weather Bur. 191 7. 



