AGEICULTURA.L BOTANY. 320 



It was found that tbere was a remarkable difference between monovalent and 

 bivalent cations in their effects on permeability. While none of the monovalent 

 cations, except hydrogen, are able to decrease permeability, all of the bivalent 

 cations so far investigated (Mg, Ca, Ba, Sr, Mn, Co, Fe, Ni, Zn, Cd, Sn) are able 

 to do so to a marked degree. 



The production of anthocyanins and anthocyanidins, II, A. E, Everest 

 (Proc. Roy. Soc. [London], Ser. B, 88 (1914), No. B 60S, pp. 326-332).— In a 

 previous paper (E. S. R., 31, p. 626) the author showed that the red pigments 

 obtained as the result of careful reduction of the yellow flavonol derivatives are 

 identical with the natural anthocyans of plants. This point having been contro- 

 verted, he has repeated some of his investigations and shows that by the reduc- 

 tion of flavonol glucosids, the yellow pigments present in many flowers, a series 

 of red pigments may be obtained whose properties agree with those of the 

 anthocyanins. 



Apart from the question of anthocyan the author reports that where he 

 obtained an anthocyan by reduction of the flavone or flavonol present in the 

 flower extracts, he was able to show that the pigment was an anthocyanin. 

 It would therefore follow that in each case the flavone or flavonol derivative in 

 the plant must have been present in the form of a glucosid. 



A comparative study of oxidation by catalysts of organic and inorganic 

 origin, A. J. Ewaet (Proc. Roy. Soc. ILondon], Scr. B, 88 (1914), No. B 603, 

 pp. 284-320). — This paper is a report of investigations carried out on the 

 influence of poisoning on apples and potatoes, and in the author's judgment it 

 necessitates a general revision of the oxidase ferments, in particular a general 

 comparison with metallic oxidases. Detailed studies are given of ajiple and 

 potato oxidase, and a comparison is made with inorganic catalysts, as well as 

 oxidases from a number of different species of plants. 



The author claims there is no justification for the use of such terms as 

 peroxidase, catalase, etc., to indicate specific substances, ferments, or groups of 

 ferments. It is, however, permissible to use such terms as catalase action or 

 peroxidase action. Comparison with metallic oxidases shows that there is at 

 present no reason for assuming the existence of si^ecifically distinct plant 

 oxidases. 



Cytological studies of Azotobacter chroococcum, A. Bonazzi (U. S. Dept. 

 Agr., Jour. Agr. Research, 4 (1915), No. 3, pp. 225-241, pis. 3). — From these 

 studies as described, the author concludes that the cells of A. chroococcum pre- 

 sent a complex nature and different stadia of cytological make-up. The organ- 

 ism shows peculiar granulations apparently not related to reproduction. These 

 take the basic dyes and are constituted neither of fats nor glycogen, starch nor 

 chromatin, but appear to be of a metachromatic nature. They seem to have 

 their genesis from the nucleus. Their disposition in the cells is not constant, 

 but changes in different individuals. Their regular api^earance in the cells of 

 A. chroococcum might be caused by the special conditions of life. 



A bibliography is given. 



Physiological studies of Bacillus radicicola of Canada fi.eld pea, M. J. 

 Prucha {New York Cornell Sta. Mem. 5 {1915), pp. S3).— In view of the fact 

 that the results of inoculating legumes with pure cultures have not always 

 proved satisfactory, the author has carried out extensive investigations involv- 

 ing the isolation and identification of the organism causing nodule development 

 on the roots of the Canada field pea, a study of the influence of various factors 

 on nodule development on the plant when in water or soil cultures, and a study 

 of the influence of various environmental conditions on the infecting power of 

 the organism. It is stated that the causal organism is B. radicicola. 



