iqiq) current literature 103 



close relationship between the maximum summer rainfall and the grasslands 

 of the country. 



The second publication'^ contains relief and precipitation maps of the 

 world and numerous larger and smaller maps showing the agricultural produc- 

 tion of all lands. Many other data are contained in the text and in various 

 tables. Several recent papers have successfully related crop possibilities to 

 natural vegetation, but these maps provide material for reversing the process 

 and of relating natural vegetation to areas of crop production. — Geo. D. 

 Fuller. 



Seedling of dicotyledons. — Sinnott'' has made a comparative study of 

 the seedling throughout dicotyledons, in order to distinguish between conserva- 

 tive and variable characters. It is a very timely distinction to emphasize, 

 for the application of the law of recapitulation to variable characters has led 

 to more or less confusion. The number of protoxylem poles is found to be a 

 very variable character. More constant is the relation between the vascular 

 system of the hypocotyl and that of the epicotyl, two main types being recog- 

 nized. The venation of the cotyledon was found to be very constant; and 

 also an odd number of veins was found to characterize the seedling of all 

 dicotyledons, distinguishing it from that of the gymnosperms. The most 

 conservative character is the structure of the cotyledonary trace. — ^J. M. C. 



Monographs on experimental biology. — The first volume of a series of 

 monographs dealing with experimental biology and general physiology has 

 appeared under the editorship of Jacques Loeb, T. H. Morgan, and W. J. V. 

 OsTERHOUT. The first monograph^" deals with forced movements, tropisms, 

 and animal conduct. Among the monographs in preparation are "The chromo- 

 some theory of heredity" by T. H. Morgan; "Inbreeding and outbreeding; 

 their genetic and sociological significance," by E. M. East and D. F. Jones; 

 "Pure line inheritance," by H. S. Jennings; "The experimental modification 

 of the process of inheritance," by R. Pearl. 



This series represents an important event in American science, and deserves 

 the cooperation of the scientific men of the country. — J. M. C. 



A new phytopathological journal. — The first number of the Annals of the 

 Phytopathological Society of Japan has just appeared, including 5 papers. 

 Some of the papers are in English, and those in Japanese include a summary 

 in English, so that all of them are available for foreign botanists. The contrib- 

 utors to this first number and their titles are as follows: M. Shirai, "On the 



•8 Finch, V. C, and Baker, O. E., Geography of the world's agriculture. loX 

 13.5 inches, pp. 149. jigs. 207. 1917. 



'' SiNNOTT, E. W., Conservatism and variability in the seedling of dicotyledons. 

 Amer. Jour. Bot. 5:120-130. figs. 4. 1918. 



^"LoEB, Jacques, Forced movements, tropisms, and animal conduct. 8vo. 

 T^Y). 2og. figs. 42. Philadelphia: J. B. Lippincott Co. 1918. $2.50. 



