FIELD CHOPS. 133 



from existing chromogens but is the result of ;iii increasecl couteut of the more 

 important carbohydrates. With the increase of sugars and the acceleration of 

 oxidation, there is a decided increase in the glucosids, and a considerable por- 

 tion of this increase is anthocyanin. 



Oxidases and peroxidiastases, D. Brocq-Rousseu and E. Gain {Rev. G6n. 

 Bot., 21 {J 909). No. 2Ji2, pp. 55-62, fig. 1). — In previous publications (E. S. R., 

 20, p. 130) the authors have shown the wide distribution of peroxidase in seeds 

 and also the duration of that enzym in old seeds, and the present note gives an 

 account of investigations to obtain oxidase from the seeds of morning-glory. 

 Oxidase is known to be very active in these seeds, but all attempts to isolate it 

 failed ; in every case the precipitate gave a reaction of peroxidase without any 

 trace of oxidase. This raised the question of the relationship between the two 

 diastases. 



The occurrence of urease in higher plants, T. Takeuchi {Jour. Col. Apr. Imp. 

 Univ. Tokyo, I {J 909), Xo. 1, pp. 1-1. 't). — In studying the enzyms of some of 

 the higher plants, the autlior discovered in the resting seeds and seedlings of 

 the soy bean a powerful urease, which demonstrates that this substance exists 

 not only in lower organisms but in higher plants as well. 



An experimental study of acclimatization, J. W. Habshbergeb (Proc. Acad. 

 Nat. Sci. Phila., 61 (1909), pt. 1, pp. 57-110).— \ study has been made of the 

 sequence of the opening of buds of various species of plants. 



The experiments were conducted with a number of different varieties of twigs 

 obtained near Philadeli)hia and their normal development compared with that 

 induceil by various chemicals. The following spring twigs of 20 species and 

 varieties of perennial plants were obtained from 12 different localities and the 

 effect of the chemicals in altering the normal se<iuence of bud development was 

 investigated. In general the sequence of develoi)ment was maintained, showing 

 that acclimatization had occurred, and the differences in the time of bud devel- 

 opment illustrated the extent to which the variations had become established. 



Studies in symbiosis, N. Bernard {Ann. Sci. Nat. Bot., 9. ser., 9 {1909), Nos. 

 1, pp. 1-6 'i. figs!. 12; 2-^3, pp. 65-192. pis. .'/, figft. 16; ',-5, pp. 193-196).— In a 

 previous paper (E. S. R., 14, p. 635), the author has shown the dependence of 

 many species of orchids on fungi for their germination and subsequent develop- 

 ment. In the present article a detailed account is given of the interrelation- 

 ship of the two organisms. In many cases species of Rhizoctonia appear to be 

 symbiotically associated with orchids, although it has been found possible in 

 artificial media to secure germination by increasing the concentration, the 

 result of this being the same as that produced by the fungus. Other conditions 

 equivalent to symbiosis are described. 



A bibliography of mycological literature, G. Lindau and P. Sydow ( Thesau- 

 rus litteratiira' mycologicw et Jichcnologicw ratione habita prwcipue omium 

 quw adhuc scripta sunt de mycologia appUcata. Leipsic, 1909, vol. 2, pt. 2, pp. 

 S21-808). — This is the concUision of the work previously noted (E. S. R., 21, p. 

 33), the total number of papers represented being 29,750. 



FIELD CROPS. 



Dry farming: Its principles and practice, W. Macdonald {New York, 1909, 

 pp. XIV+290, pis. 32). — This work devotes a chapter each to the following 

 topics : History of dry farming, some points in practice, the conservation of soil 

 moisture, rainfall and evaporation, the problem of tillage, the Campbell system, 

 dry-farming zones, dry-land crops, the traction engine in dry farming, and dry- 

 land experiments. 



