No. 403.] REVIEWS OF RECENT LITERATURE. 611 
Rothamsted Experiments.' — The present account by Lawes and 
Gilbert continues the results derived from forty-four years of contin- 
uous experimentation upon the same land. The general results so 
far reached show very characteristic differences in the composition 
of the ashes of different crops according to the amount of nitrogen 
they assimilated; and upon this is based the conclusion that “ inde- 
pendently of any specially physiological function of the bases, such 
as that of potash with the formation of carbohydrates, their office 
was prominently also that of carriers of nitric acid, and that when the 
nitrogen had been assimilated, the base was left as a residue in com- 
bination with organic acid, which, according to the character of the 
plant, was represented more or less completely by carbonic acid in 
the ash.” Ly: P. P. 
Plants in Calcareous Tufa.? — Mr. J. M. Hulth presents an inter- 
esting study of the plants found in the calcareous tufa of western 
Gothland in the region of Falkóping and Skófde, and discusses the 
vegetation of seven different horizons with respect to their relation 
to the flora of the Arctic, Boreal, and Atlantic periods. The vegeta- 
tion found corresponds with existing types. D. P. P. 
Fossil Flora of the Cascade Range.’ — Studies of the fossil plants 
associated with the lavas of the Cascade Range, prosecuted during 
the last five years, have been completed by Professor F. H. Knowlton. 
Twenty-eight forms in all are described, and they include such types 
as have hitherto been found in the Miocene only, from which the 
author concludes unhesitatingly that the beds are of Miocene age. 
DEBE 
Flora of the Coal Layers of Là Ternera.* — Solms-Laubach pre- 
sents a short account of the plants derived from the Coal Formation 
! Lawes, Sir J. B., and Gilbert, Sir J. H. Agricultural, Botanical, and Chemi- 
cal Results of Experiments on the Mixed Herbage of Permanent Weed Land; III, 
Chemical Results, PA. Trans. R. Soc., vol. cxcii (1900), pp. 139-21 
? Hulth, J. M. Ueber ed te aus Westergótland, Bu//. gm Inst. of 
Upsala, 1898, vol. iv, pp. 5-40, P 
? Knowlton, F. H. Report on as Fossil Plants associated with the Lavas of 
the Cascade Range, U. S. Geol. Surv., vol. xx, III, 1898-99, pp. 37-52, Pls. I-VI. 
t Solms-Laubach, H. von Grafen zu. Neue Jahrb. f. Mineral., etc, vol. xii, 
1899, pp. 581-609, Pls. XIII, XIV. 
