I'lELD CROPS. . 620 



such a study are as promising as tliose furnished by a study of any other 

 meteorolof^ical element. 



Biological researches on protective contents of plants, W. Peyee (Flora, 

 n. ser., 3 {1911), No. //, pp. 4Jf1-Jf78). — This is a report on certain proi^erties of 

 plants studied in relation to their protection against animals. These protective 

 properties are apparently either chemical or mechanical, and are objectionable 

 probably because of taste, smell, structure (hairy or crystalline), etc., or perhaps 

 on account of some subtler effect which suggests their hurtful or deadly nature, 

 as in the case of poisons. 



Details are given and tabulated, with effects observed on animals eating 

 objectionable plants after 24 hours of hunger, etc. The needle-like crystals of 

 oxalate of lime are found in many plant cells. These are mechanically offensive 

 to mucous membranes, more so than broken glass, coal splinters, copper filings, 

 or fish bones, besides which by wounding surfaces they give quicker circulation 

 to poisons, etc. This makes their presence a peculiarly effective form of pro- 

 tection. The same is true in a less degree of other common crystals. 



Literature of tropical economic botany and agriculture, 1899—1910, I, II, 

 J. C. Willis ([Ceylon: Roy. Bot. Gard.], pts. 1, pp. 62; 2, pp. Jf5). — This is a 

 list of the more important articles that have appeared in books, journals, and 

 other publications relating to tropical plants of economic importance. 



Seeds and plants imported during the period from January 1 to March 31, 

 1911— Inventory No. 26 (U. 8. Dept. Agr., Bur. Plant Indus. Bui. 233, pp. 

 98).- — A list is given of 1,134 seeds and plants which were introduced during 

 the period indicated above. These represent miscellaneous collections. A 

 considerable portion, however, was secured by Mr. F. N. Meyer in Asia. 



FIELD CROPS. 



Guide to experiments for 1911, D. A. Gilchrist (Coimty Northum'h. Ed. 

 Com. Bui. 16, pp. 5-13, figs. 2). — This reports a continuation of work at Cockle 

 Park, previously noted (E. S. R.. 24, p. 34). 



In view of the results of fertilizer experiments on meadows, pastures, and 

 various rotations, the author concludes " that dung is of considerably more 

 value than artificials for this light soil, but both give satisfactory results." 

 The use of dung alone was followed by practically as heavy crops of roots as 

 when artificial fertilizers also were used, but the residual effect upon the 3 fol- 

 lowing crops was greater in the case of the mixture. In rotations the best 

 results followed the use of dung only for swedes and a complete mixture of 

 commercial fertilizers on the hay crop. A division of the total amount of 

 fertilizer over 3 hay crops in the rotation did not prove advantageous. " Lin- 

 seed cake fed to sheep when eating off the roots has greatly increased the 

 following corn crop, but the subsequent crop to a small extent only." " Sulphate 

 of ammonia has had distinctly exhausting results except on the crops to which 

 it was applied." In the absence of a potash source almost no gains were ob- 

 tained from artificial fertilizers, but a moderate application of dung did much 

 to remedy this deficiency on this light soil. 



A table states the results of a variety test of oats conducted during the period 

 1906-1910 inclusive. In 1910, 10 varieties were tested, the highest yield being 

 produced by Payrent which yielded 65J bu. of 42 lbs. each per acre. In a test 

 of varieties introduced from Canada, Thousand Dollar yielded 57f bu. and 

 Banner 56^ bu. Both varieties gave from 13 to 15 bu, more per acre when 

 brought directly from Canada than after they had grown at Cockle Park for 

 some years. In a test of 6 barley varieties the highest yield in 1910 was pro- 



