NOTES AND COMMENT 



Thi-ee numbers have appeared in the second volume of Physiological 

 Researches, as follows: The Cryoscopic Constants of Expressed Vege- 

 table Saps, as Related to Environmental Conditions in the Arizona 

 Deserts, by J. Arthur Harris and John V. Lawrence, with the cooper- 

 ation of R. A. Gortner; Further Studies of Foliar Transpiring Power 

 in Plants, by A. L. Bakke and B. E. Livingston; An Analysis of the 

 Causes of Variations in the Transpiring Power of Cacti, by Edith B. 

 Shreve. The fourth number, now in press, is by Forman T. McLean, 

 and describes his work on the correlation between plant growth and 

 clmiatic conditions in Maryland. 



Mr. L. S. Murphy has prepared a bulletin on the Forests of Porto 

 Rico (U. S. Agr. Dep. Bull. 354), with special reference to the probable 

 character of the original forests and the possibility of increasing the 

 present forest production. Porto Rico now has a rural population of 

 260 per square mile, and uses three times as much wood per annum as 

 is produced by its forested areas. There is a small body of rain- 

 forest in the Luquillo Mountains, which was formerly surrounded by a 

 low deciduous type of xeroph5i;ic forest, occupying most of the lower 

 portions of the island. 



The H. W. Wilson Company, of White Plains, N. Y., is publishing 

 an Agricultural Index, which lists and classifies the articles in all state 

 and national agricultural bulletins and in about sixty magazines and 

 journals. The index comprises titles in scientific, practical, and edu- 

 cational subjects in every branch of agriculture, horticulture, and 

 forestry. The charge to libraries is determined by the number of indexed 

 magazines for which the library subscribes. 



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