1922] CURRENT LITERATURE 231 
originated in the Devonian and flourished in the lower and cate Culm in 
Basse-Loire and during the Westphalian in the north.—A. C. 
Availability of potassium.—BREAZEALE and Briccs* find that the potas- 
sium of orthoclase solutions is not available for wheat seedlings, owing, it is 
concluded, to the potassium being present with other elements in a complex 
solute molecule, which does not yield potassium ions. This conclusion is 
supported by the fact that oxidation with acids makes the potassium available. 
From the experiments recorded in the paper, the general conclusions are drawn 
cluded from experiments of this kind that plants cannot get the needed potas- 
sium from finely ground orthoclase applied to the soil or from orthoclase found 
naturally in the soil. The nature of the root system and the conditions of its 
functioning are probably quite different in the solution than in the soil.— 
Indian Gondwana plants.—A great majority of the specimens described in 
this volume were figured by FrIstMANTEL in the Palaeontologia Indica. A 
revision’s of the material brought to light some new features, and in several 
instances has revealed inaccuracies in the illustrations accompanying FEtst- 
MANTEL’s descriptions. Numerous text illustrations and seven plates in folio 
with excellent drawings and photographs enable the reader to judge SEWARD’S 
revision of Gondwana plants. SEWARD was ably assisted by SAHNI, who 
promises to become an authority on Indian paleobotany. 
The Gondwana system is an extremely interesting geologic period of high 
Paleobotanic importance. It corresponded to the Permo-Carboniferous of 
Tepresented, but ae peeya ae tiee are rather scarce. No Glossopteris is 
mentioned.—A. C. N 
New method of vegetative multiplication——Dastur and Saxton* have 
described a method of vegetative multiplication in a perennial species of 
4 BREAZEALE, J. F., and Briccs, L. J., Concentration of potassium in nage 
solutions not a measure of its availability to wheat seedlings. Jour. Agri es. 
20: nla 1921 
Sewarp, A. C., and Saunt, B., Indian age plants: A revision of Palae- 
ontologia Psat be New Series 7:1-42. pls. I-7. 
and Saxton, W. T., A uew mth “ —_ multiplication 
Da as 
in Crotalaria burhia. "New Phytol. 20:228-233. figs. 
