1913] CURRENT LITERATURE 175 
©.5 per cent solution of sodium nitrate, they suffer little or no injury. Pea 
seedlings die in 2 days in ao. 5 per cent of sodium oxalate, but are still uninjured 
in an “sega strong solution of sodium acetate. 
In Spirogyra the first structure to show the effect is the nucleus, which © 
contracts and becomes lens-shaped. A little later the chloroplasts begin to 
contract. Lorw finds that the effect is not due to acidity, since 0.005 per cent 
of oxalic acid is more injurious than o.o1 per cent of citric acid, and 0. o0or per 
cent more injurious than o.oo1 per cent of tartaric acid. 
Loew concludes that the injurious effect of the oxalates is due to the 
extraction of calcium from the nucleoproteins, chromatin, and plastin, and its 
replacement by potassium or some other element, and their bringing about a 
change in the imbibing power of the different parts of the protoplasm. He 
thinks that sigan is an essential element in the cells of the higher animals and 
plants—J. N. Martin. 
Sutcliffia.—Miss Dr FraAIne” has made a painstaking investigation, by 
means of the well known wax plate method of modelling, of the vascular 
system of Swfclifia, a new genus of the Medulloseae established by Scort. 
Unfortunately the specimen is rather badly dilapidated and for that reason a 
certain reserve is necessary ininterpretation. The vascular system as described 
by Miss Dr Fratne consists of a large axial “protostele” (sic!) surrounded by 
three more or less clearly identifiable “meristeles.” In addition to these are a 
number of “extrafascicular” bundles. By a process of reasoning which it is 
difficult to follow, the author identifies the central “protostele” with the ring 
of bundles in the Cycadales. It would seem to be in accordance with the 
general principles of vascular anatomy to regard it as a medullary bundle, and 
the three surrounding strands as corresponding to the cylinder system of 
bundles, a conclusion rendered extremely probable by the fact that it is with 
these that the leaf traces become continuous. Suécliffia is considered to be a 
primitive type regardless of the fact that it has an extremely multifascicular 
foliar supply. This would appear to be entirely against all established 
Principles of anatomy. It is gratifying to find that English authors are 
gradually coming around to the standpoint in regard to the affinities of 
Cycadales, namely as rather with the Medulloseae than the Lyginodendreae, 
which has been held in continental Europe and this country for more than a 
decade.—E. C. JerFrrey 
Cause of leaf fall.—In a limited series of experiments conducted with 
detached twigs of various deciduous trees placed in water in a saturated 
atmosphere, VARGA’ has attempted to establish the relationship between this 
™ De Frarne, E., On the struct d affinities of Sutclifia, in the light of a newly 
discovered specimen. Ann, Botany 26: 1031-1066. figs. 10 “pls. gl, 02. 1912. 
* VarGa, Oskar, Beitriige zur Kenntnis der Beziehungen des Lichtes und Tem» 
Peratur zum Laubfall. Oesterr. Bot. Zeitschr. 61: 74-88. 1911. 
