METEOROLOGY. 29 



Sexual reproduction in plants, M. Mobius {Biol, Cenihl., 16 (1S96), pp. 129- 

 153, Jigs. 10; ahs. in Jour. Roij. Micros. Soc, 189G, Xo. 3, p. 3.28). — The absence of sex- 

 uality in many groups of plants is couimentetl upon and sexual reproduction is 

 regarded as liaviug a twofold function, the uuiintenauce of stability by the elimina- 

 tion of acquired characteristics and tlie production of new varieties and species by the 

 union of difterent germ plasms. The crossing of species is hehl to be more common 

 than is generally believed. 



A contribution to the knowledge of germination, D. Prianisciixikow (Zandio. 

 Vers. Stat., 40 {ISDG), Xo. G, pp. 4J0-470). 



A contribution to the biology of variegated leaves, E. Staiil (Ann. Jard. Bat. 

 Buitenzorg, 13, pp. 137-216, pls.2 ; abs. in Bot. Ztg., 54 {1896), Xo. 14, pp. 209-215). 



Honeydew, J. Van der Plank and M. P. Biourge (La Cellule, 9 {1896), pp. 375- 

 399 ; ahs. in Jour. Boy. Micros. Soc, 1896, Xo. S, p. 321). — The authors collected some 

 of the exudation from the copper beech and found it was composed of a mixture of 

 gum, dextrin, and levulose. When incinerated it gave 1.55 jier cent ash composed 

 of C'aO, MgO, and KjCO;. 



Concerning the presence of arganin in the roots and tubers of certain plants, 

 E.ScHULZE {Landw. Vers. Stat., 46 {1896), Xo. 6, pp. 451-458). 



On the presence of pectic substances in the epidermal cells of the roots of 

 Equisetum, L. Vidal {Jour. Bot. France, 10 {1806), Xo. 14, pp. 2.J6-2.39, figs. 2). 



A contribution to the knoAvledge of lignified cell membranes, H. C. Schellen- 

 beik; {Inaug. Diss. Zurich, 1895, pp. 36; abs. in Bot. Centbl. Beihefte, 6 {1896), Xo. 2-3, 

 pp. 115, 116). 



Researches on the intervention of atmospheric ammonia in the nutrition of 

 plants, A. MuNTZ {Ann. Sci. Agron., ser. 2, 1 {1896), Xo. 2, pp. 161-214, figs. -5). 



On the presence in Monotropa hypopithys of a glucosid of methylsalicylic 

 ether and on the hydrolyzing ferment of this glucosid, E. Bourquelot {Compt.^ 

 Rend., 122 {1896), Xo. IS, pp. 1002-1004; Bev. Sci., ser. 4, 5 {1896), No. 20, p. 629). 



Assimilation of nitrogen by fungi, K. Puriewitsch (Be/-, deut. bot. Ges., 13 {1895), 

 Xo. 8, pp. 342-345; abs. in Jour. Boy. Micros. Soc, 1896, Xo.3,p. 334). — Experiments were 

 conducted with Aspergillus niger and Penicillium glaucum and the author concludes 

 that they can absorb nitrogen from the air only when there is present in the nutrient 

 solution a sufficient amount of sugar. 



A contribution to the nitrogen question, -T. H. Aeby {Landw. Vers. Stat., 46 

 {1896), No. 6, pp. 409-439). 



METEOROLOGY. 



The work of the station of agricultural climatology of Juvisy, 

 France, in 1895, 0. Flammarion [Bui. Min. Agr. France, 50 {1896), 

 N't). 2, PI). 257-284, Jig. 1). — The observatious of this station are sum- 

 niaiized with reference to the action of solar radiation on the atmos- 

 phere, the soil, and the plant. A record for 18 years (1878-'05) shows 

 the greatest solar activity in 1893. A close correspondence is shown 

 between the cnrves representing the occurrence of sun spots and the 

 mean annual temperature for the period from 1879 to 1895. The tem- 

 perature .( — IG^ C.) in February was the lowest observed since 1710. 

 While February was excessively cold, September was excessively hot, 

 reaching the maximum for the year (33.7° C, September 7). Such a 

 temi)erature for tliis month has not been observed since the invention 

 of the thermometer, the average for the month (19.1° C.) being 3 



