1910] CURRENT LITERATURE 399 
broken on the side of the greatest enlargement, so that in cross-section it appears 
as a crescent partly inclosing the gall. The vascular bundles are pushed apart 
on the side where the swelling is greatest, and in cross-section form a crescent 
pattern instead of a ring. Small vascular bundles penetrate the tissues of the 
The nutritive tissue is abundant and the sclerenchyma tissue is more abun- 
dant than in most lepidopterous galls——MeEt. T. Cook. 
Light and germination.—Where light was supposed to be necessary for any 
considerable germination, LEHMAN finds? that in Ranunculus sceleratus other 
stimuli can be substituted for light. One per cent Knop’s solution gives a greater 
percentage of germination in darkness than distilled water in light. In contrast 
to wet filter paper generally used as a substratum in such experiments, earth was 
found to stimulate germination greatly, water extracts of earth made by boiling 
were less effective, and extracts made with cold water showed no stimulation. 
If these seeds are exposed to germinative conditions in darkness for twenty or 
more days, light is then not effective. The author calls such seeds “dunkel- 
harten” or ‘‘dunkelstarren,” in contrast to the “‘lichtharte” seeds of Nigella.s° 
Stellaria media, indifferent to light in its germination, was greatly stimulated by 
such substrata as Knop’s solution and earth_—WILLtaM CROCKER. 
Selaginella preissiana.—The extremely small xerophytic Selaginella preis- 
stana, found in West Australia, Victoria, and Tasmania, is described by BrucH- 
MANN.5' ‘The cotyledons are slightly larger than the foliage leaves. The first 
dichotomy gives an erect branch about 3°™ high; the other branch becomes the 
creeping rhizome, which gives off erect shoots right and left. Growth is by means 
.of a single polyhedral apical cell. The stem is protostelic, the hypocotyl having 
a single exarch protoxylem point. 
In the root there are three groups of initials: periblem and plerome having 
a common group, and dermatogen and calyptrogen each having a group. Root 
hairs are wanting, and epidermis and cortex are infested with an endophytic 
fungus. The hyphae were observed penetrating the epidermis from the soil.— 
W. J. G. Lanp. 
Cellulose-forming enzyme.—In continuing his capillary analysis of enzymes, 
Griisss? claims to have found, as his most important result, a cellulose-forming 
enzyme which he terms cytocoagulase. The material condensed was dissolved 
49 LEHMAN, Ernst, Zur Keimungsphysiologie und Biologie von Ranunculus 
Sceleratus L. und einiger anderen Samen. Ber. Deutsch. Bot. Gesell. 2'7:476-494. 
5° KINZEL, WILHELM, Ueber den Einfluss des Lichtes auf die Keimung. “ Licht- 
harte” Samen. Ber. Deutsch. Bot. Gesell. 25:269-276. 1907. 
cares H., Ueber Selaginella preissiana Spring. Flora 100:288-295. 
Jigs. 8. 19 
? GRrtss, I. Kapillaranalyse einiger Enzyme. II. Ber. Deutsch. Bot. Gesell. 
Wary 1909. 
