1907] CURRENT LITERATURE 295 
is negatived by the observation of UrsprunG5s that the pith of such plants as 
Sambucus and Tectona increases considerably in diameter after the wood cylinder 
is formed. This can be brought about only by expansion and division of the 
elements of the wood. The author holds that vessels can increase in diameter 
after they have lost their living contents—M. A. CHRYSLER 
Waterbloom.—MOstivs°° reports that for several years a waterbloom has 
appeared each summer in the botanical garden in Frankfurt, and that it is regu- 
larly composed of three species of Cyanophyceae: Oscillatoria Agardhii Gomont, 
aena flos-aquae Bréb., and Clathrocystis aeruginosa Henfrey. The appear- 
ance of Oscillatoria in the association has not been noted hitherto. An abnormal 
form of Cladophora crispata (Roth.) Kiitz. is also described—Cunartes J. 
CHAMBERLAIN. 
Abnormal mosses.—Two interesting abnormalities are described by 
Gy6rFry,37 collected in the High Tatra. A specimen of Plagiobryum demissum 
Lindb. shows the seta forking at the apex and carrying two perfect capsules; 
and one of Polytrichum alpinum L. has two setae, each carrying a normal capsule, 
both covered by a single calyptra. Brucu records a like case in P. juniperinum. 
Obviously these forms have arisen from a single egg—C. R. B. 
Respiration.—KostyTscHEw declares that in the aerobic respiration of the 
leaves of seed plants which contain mannit, hydrogen is produced; but in anae- 
robic respiration, even when very vigorous, not a trace is set free.36 The experi- 
ments were designed to test the results of Muntz (1876) and DeLuca (1878), 
which antedated bacteriological knowledge, that H is produced by mannitiferous 
fungi and seed plants in anaerobic respiration.—C. R. B 
Anatomy of Urticaceae.—RENNER®® has published a detailed account of the 
anatomy of Artocarpeae and Conocephaleae, paying special attention to Ficus. 
A systematic presentation of the tribes follows, the anatomical structure being 
used as a basis of discussion —J. M. C 
35 UrspruNnG, A., Ueber die Dauer des primaren Dichenwachstums. Ber, 
Deutsch. Bot. Gesells. 24: peas 1906. 
3° Més ., Algologische SG PETES LE iiber eine Wasserbliithe und eine 
ideeeal ees igia 46:279-287. 1907. 
37 GyOrFFy, I., Bryologische inti zur Flora der Hohen Tatra. IV. Hed- 
Wigia 46:262. 1907. 
KostytscHEw, S., Zur Frage iiber die Wasserstoffausscheidung bei der 
a der Samenpflanzen. Ber. Deutsch. Bot. Gesells. 24: 436-441. 1906. 
39 RENNER, OrrTo, Beitriige zur Anatomie und Systematik der Artocarpen und 
ehencinsy insbesondere der Gattung Ficus. Bot. Jarb. 39: 319-448. 1907. 
