AGRICULTURAL BOTANY. 225 



In mixtures of the nitrates of calcium and magnesium, the greater absorp- 

 tion of the latter ion in comparison with that of potassium appears, as also 

 does the great significance of even a small proportion of calcium. 



In unmixed solutions, the magnesium ion is much more favorable to absorp- 

 tion in the weaker concentrations, the potassium ion in the highest, absorption 

 of these two being about equal at a concentration of 360 NXIO— '. Absorp- 

 tion from mixtures exceeds that from either solution singly, except in the weak- 

 est concentrations. It appears probable that a large proportion of magnesium 

 is more favorable in weaker concentrations. 



On alfalfa laccase, H. H. Bunzel (Jour. Biol. Chem., 20 (1915), No. 4, PP- 

 697-706, fig. 1). — The author has reported work bearing upon the conclusions 

 of Euler and Bolin (E. S. R., 22, p. 115) regarding the existence of a laccase as 

 an oxidase in Medicago sativn. The simplified oxidase apparatus and method 

 previously described (E. S. R., 32, p. 508) were employed. 



It is claimed that the effect of salts of strong bases with weak acids on tlie 

 rate of oxidation of hydroquinone by atmospheric oxygen is due entirely to the 

 concentrations of the hydroxyl ions in such solutions ; that there is no hydro- 

 quinone-oxidizing oxidase, laccase, in M. sativa; and that the accelerating effect 

 of the preparation obtained from M. sativa on the rate of oxidation of hydro- 

 quinone by atmospheric oxygen is due to the alkalinity of the solution of the 

 salts contained in that pi-eparation. 



The germinability of hard leguminous seeds, A. Pugliese {Staz. Sper. Agr. 

 ItaL, 4S {1915), No. 1, pp. 77-S2, fig. 1).—A machine and a method are de- 

 scribed by which hard leguminous seeds are subjected to the action of a scarify- 

 ing surface revolving at desired velocities and then tested in germinating ex- 

 periments. From the results given it appears that the percentages of germina- 

 tion were generally augmented by this treatment, the degree varying consider- 

 ably according to the species employed. 



On the primary and secondary sex characters of some abnormal Begonia 

 flowers and on the evolution of the monoecious condition in plants, C. J. 

 Bond (Jour. Genetics, i (1915), No. Jf, pp. 3^1-352, i)ls. 2). — Discussing two types 

 of abnormal flowers as observed in Begonia, the author holds that the presence 

 in the same flower of abnormalities of accessory and of essential floral 

 parts is important as showing that instability of equilibrium in the primary 

 sex elements carries with it in nearly all cases instability of equilibrium of 

 somatic tissues also. It is suggested that the almost universally central and 

 terminal position of the female elements in hermaphrodite flowers is a fact of 

 considerable phylogenetic importance, the female portion of the flower repre- 

 senting the undifferentiated reproductive rudiment from which the male portion 

 has segregated off during the course of evolution. 



It is thought that the association between the segregation of primary and that 

 of secondary sex characters is less intimate in plants than in animals. 



Factors influencing flower size in Nicotiana with special reference to 

 questions of inheritance, T. H. Goodspeed and R. E. Clausen (Amer. Jour. 

 Bot., 2 (1915), No. 7, pp. 332-374, figs. 4). — The authors report measurements 

 at different ages and under varying conditions of the length of the corolla and 

 spread of the limb as noted in a large number of individuals of Nicotiana, dis- 

 cussing such differences as appear to be associated with culture conditions, 

 hybridization, age of plants, anthesis, and removal of flowers. The general con- 

 clusion is reached that measurements of blooms, in order to represent the flower 

 size of a population, must extend over the greater part of the period of blooming 

 normal thereto, or else must cover an identical portion of the flowering period 

 of each plant. 



