BOTANY. 717 



McDouGALL and F. Howlks {Mem. Mavchesicr Lit. and Pliil. Soc, 44 {1900), pt. 4, 

 No.l3,2)p. 1-19; ubs. in Jour. Chcm. Soc.. [London'], 7S{1900), No. 456, JT, p. 651). — 

 Reports testa of the influence of different forms of combustion chamber, strength of 

 current, mixtures of oxygen and nitrogen, and temperature upon the rate of forma- 

 tion of nitric acid. 



On the simultaneous production of two nitrogen salts in the crater of 

 Vesuvius, R. A'. Mattelxxi {Contpt. Bend. Acad. Sci. Povw, ISl {1900), No. 23, pp. 

 963-965). 



Miscellaneous analyses, H. J. Wheeler {Rhode Island Sta. Itpt. 1899, pp. 146- 

 151). — Analyses are reported of salt, sodium carbonate, double carbonate of potash 

 and magnesia, nmriate of potash, sulphate of potash, carbonate of potash, acid phos- 

 phate, floats, Thomas slag, aluminum phosphate, waste liquor from rendering Avorks, 

 nitrate of potash, nitrate of soda, sulphate of ammonia, dried blood, cotton-seed meal, 

 and soot. 



On an improved Geissler potash apparatus, J. Wetzel {Ber. Deut. Cheni. 

 GeselL, 33 {1900), No. L'^, pp- 3393, 3394, Jig. 1). — -The improvement consists of the 

 introduction of small movable glass funnels into the absorption bulbs, which collect 

 and hold the gas bubbles for some time beneath the surface of the potash solution, 

 thus insuring more complete absorption. 



BOTANY. 



Xenia, or the immediate effect of pollen, in maize, H. J. Web- 

 ber {U. S. Dept. Ayr.. Dlrh'wn of Vegetable PhyslejJogy and 

 Pathology Bui. '22, P2^. Jf-Jf.^ jjls. Jf). — The author reviews much of the 

 more recent literature on the supposed immediate'' or direct effect of 

 pollen on the character of seeds and fruits, and gives in detail the 

 records of a number of experiments and results in crossing different 

 varieties and races of corn. The results obtained are discussed at con- 

 siderable length, and it is shown that in the experiments, particularl}^ 

 in the case of dent races with a starchy endosperm crossed with sweet 

 corn with a sugar}- endosperm, there was no indication of modification 

 of the chemical constitution. It seems probable that in a great 

 majorit}^ of cases the results conlirm Correns's proposition, viz, that 

 the influence of foreign pollen exhibits itself only in the endosperm, 

 all parts which are outside of this remaining entirely uninfluenced, and 

 that the influence extends only to the color of the endosperm and the 

 chemical composition of the reserve materials — the starch or dextrin 

 therein. In all cases the size and form of the kernels remain 

 unchanged. The experiments and observations of the author favor 

 the theory that xenia in maize is caused by fecundation of the embryo 

 sac nucleus by one of the male nuclei, as suggested by De Vries and 

 Correns; and the evidence now available seems to indicate that those 

 cases of supposed xenia where the pericarp is influenced must be due 

 to other causes or explained as errors of observation. 



On the poisonous properties of compounds of sodium, potas- 

 sium, and ammonium, H. Coupin {Rev. Gen. Bot., 12 {1900), Xo. 

 13'7\pp. 177-19->). — A report is given on the toxic equivalent of the 

 principal compounds of sodium, potassium, and ammonium in regard 



