ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 439 



hydrates the quantity of proteinaceous substances which aro not digest- 

 ible not only does not diminish, but actually increases. 



Migration of Ternary Substances in Annual Plants.* — G. Andre" 

 tinds that in Sinapis alba and Lupinus alius, at*a period of twenty-four 

 days after germination, the saccharafiable carbohydrates amount to 7*43 

 p.c. in the seed, and 13 '15 p.c. in the whole plant ; while but very little 

 increase has taken place in the insoluble cellulose. At the period of 

 flowering this has increased to an average of about 25 p.c. Vasculose 

 is not properly a carbohydrate, but is more of the nature of humic 

 substances ; it is a kind of residue of vegetable life. 



Halophytes and their Chlorine-contents, f — W. Benecke disputes 

 Diels' statement J that in plants which grow in a soil saturated with 

 sodium chloride (halophytes) the sodium chloride is being continuously 

 decomposed within the plant, accompanied by the formation of malic acid. 

 Experiments made with the same plants as those observed by Diels — 

 Salicomia herbacea and Cakile maritima — exhibited a slight increase, 

 rather than a diminution, in the amount of chloride contained at succes- 

 sive periods. 



Physics of Fermentation. §—E. Prior and H. Schulze describe quali- 

 tative experiments on the fermentation of mixtures of dextrose and 

 levulose and of maltose and dextrose, by yeast-cells. These support 

 the views that fermentation takes place inside the yeast-cell ; that it is 

 dependent on the diffusion of the sugar solution through the cell-wall; 

 that the rate of diffusion through the cell-wall varies for different species 

 of yeast-cells ; and that in a mixture of sugars the amount of each which 

 is fermented by yeast-cells varies with the osmotic pressure of each 

 sugar. 



c. General. 



Mutation Theory. || — Dr. J. W. Moll reviews a work by H. de Vries,lf 

 which he regards as making an important step in advance of — though 

 not antagonistic to — Darwin's theory of the origin of species. After a 

 review of the various theories which have attempted to account for 

 specific variations, he refers to the existence of what Jordan has called 

 " elementary species," i.e. forms derived from a common ancestor, dis- 

 tinguished from one another by characters which, although very minute, 

 are still hereditary and constant. Of these elementary species, '200 have 

 been described within the bounds of a single species proper in the case of 

 Draba verna. Quite distinct from these are those abrupt (stossiceise) 

 variations (" single variations " of Darwin), which sometimes occur, and 

 of which de Vries records a remarkable instauce in the genus Oenothera.** 

 For such variations de Vries proposes the term mutations. 



* Loniptes Rendus, exxxii. (1901) pp. 1058-60, 1131-4. 



T Lringsheim's Jahrb. f. wiss. Bot., xxxvi. (19(H) pp. 179-196. 



% Of. this Journal, 1899, p. 178. 



§ Zertschr. angew. Chem., xiv. (1901) pp. 20S-15. See Jornn. Chem. Soc, lxxx . 

 (1901) p. 262. 



|| Biol. Centralbl., xxi. (1901) pp. 257-69,289-305 (1 fig.); also Rev. Gen. de 

 Lot. (Bonnier), xiii. (1901) pp. 5-17 (10 figs.). 



^ k Die Mutations-theone u.s.w. Bil. 1, Die Enstehungd. Arten durch Mutation,' 

 Leipzig, 1901. ** Cf. this Journal, 1900, p. 609. 



