1916] CURRENT LITERATURE 165 
(yellow pigments of the cell sap) than are plants grown on the plains. They 
believe that these pigments protect the mountain plants against the high 
insolation (especially actinic rays) of their habitat. Contrary to KERNER, 
they believe that anthocyanin in the foliage of mountain plants has little 
protective significance against light, for it develops mainly in the autumn 
after the light intensity has fallen. They consider the anthocyanin in foliage 
organs as originating by the reduction of the flavone bodies and thereby offering 
a problem in cell physiology, rather than being of physiological significance. 
They do not deny that anthocyanins of the brilliantly colored mountain flowers 
are of significance as light screens. They also emphasize the protective function 
of flavone bodies in the white and yellow flowers. The mountain plants show 
a great reduction in flavone content when they are grown on the plains. Fora 
general statement of the chemical side of this problem the reader is referred 
to a recent review upon anthocyanins.%—WILLIAM CROCKER 
Morphology of Isoetes japonica.—West and TAKEDA” have investigated 
this species, rather widely distributed in Japan, and the largest species of the 
genus known, the stem (“‘caudex” of the authors) of an old plant often attain- 
ing 4 cm. in diameter, and in very large specimens a diameter of 8 cm. may be 
reached. The trilobed caudex consists of two distinct structures, stem and 
rhizophore, to kona the ares and roots are attached Tespectively, but on 
account of the st between 
the two organs is lost. The stem apex is a conical mass of tissue at the base 
of the funnel-shaped depression in the cortex, and in this protuberance no 
apical cell can be distinguished. The primary vascular axis is “a non- 
medullated monostele,”’ and no secondary xylem is formed in this species. 
The rhizophore, a distinct root-bearing organ, is regarded in Jsoetes “as an 
organ sui generis.” The anatomy of stem, rhizophore, and leaf is described 
in detail. The authors conclude that Isoetes “occupies an isolated position 
amongst recent vascular ik me and is regarded as the sole living repre- 
sentative of the class Isoetales.”—J. M. C. 
Permeability.—Firrinc* finds the plasmolytic method rather serviceable 
for studying the intake of salts by the cells of various plants, especially Rhoeo 
discolor, which was used mainly in the investigation. Permeability to salts of 
alkali metals (K, Na, and Li) is rather great. It varies with the leaf and is 
greatest in summer and very slight in winter. The permeability for sodium 
and potassium salts was about equal arid for the lithium salts considerably 
lower. . The permeability was largely determined by the anion, the sulphate 
' ™ Bor Gag. 61:349-352. 1916. 
* West,.Cyrit, and TaKepA, H., On Isoetes japonica A.Br. Trans. Linn. Soc. 
London 8: 333-376. pis. 23-40. figs. 20. 1915. 
* Firtinc, Hans, peter oe iiber die Aufnahme von Salzen in lebende 
Zelle. Jahrb. Wiss. Bot. 56: I~64. 
