44 
8UMMARY OF CURRENT RESEARCHES RELATING TO 
BOTANY. 
A. GENERAL, including' the Anatomy and Physiology 
of the Phanerogamia. 
a. Anatomy. 
(1) Cell-Structure and Protoplasm. 
Energid Theory of Sachs.* * * § — Herr A. Hansen vigorously attacks 
Sachs’ Energid theory, which he declares does not assist in solving any 
problems of vegetable biology, and often leads to absurdities, as when 
Kollicker speaks of “ multinucleate energids,” a contradiction in terms. 
Sachs himself terms the Siphonete “ non-cellular,” and at the same time 
defines a cell as a cell-wall enclosing one or more energids, a definition 
which would include the Siphoneae. Cladophora, the separate cells of 
which are multinucleate, would have to be considered as a colony of 
colonies, or a colony of small simple Siphoneae. 
Action of Oxygen on the Movement of Protoplasm. j — Herr W. 
Kiihne describes the effect of various reducing agents on the vital 
movement of protoplasm in the hairs on the filaments of Tradescantici. 
Pulverised iron arrested the movement immediately or within 5-15 in. ; 
the power of recovery remained for two or three hours. In Nitellci the 
protoplasm retains its power of streaming without access of oxygen for 
a comparatively long period, even as much as half an hour. 
Accumulation of Protoplasm in Curved Pollen-tubes. | — Herr E. 
Mitschka finds that the pollen-tubes of Narcissus Tazetta germinate 
freely in a 7 per cent, solution of cane-sugar, and frequently assume a 
curved serpentine form ; and there is then always found a considerable 
accumulation of protoplasm on the concave portions of the wall of the 
tube. Contrary to the statements of Wortmann with regard to a similar 
phenomenon in the case of liyphae of Phycomyces nitens , this accumula- 
tion is the result, not the cause, of the curvature of the tube. Similar 
phenomena were observed in the pollen-tubes of Camellia japonica and 
Digitalis ambigua. 
( 2 ) Other Cell-Contents (including- Secretions). 
Leptomin.§ — Herr M. Raciborski gives further instructions for the 
micro-chemical demonstration of the presence of leptomin, and dissents 
from Griiss’s proposal for the distinction of three classes of oxydases. 
There is no good distinction between the (3 and the y class ; the diastases 
of the higher plants would belong sometimes to one, sometimes to the 
other class. 
Iron in Plants. || — Herr J. Stoklasa coufirms the statement of Molisch 
that iron is not a necessary constituent of chlorophyll. He finds, on 
* Biol. Centralbl., xviii. (1898) pp. 725-36. 
t Zeitsclir. f. Biol., xxxv. (1897) pp. 43-67 ; xxxvi. (1898) pp. 1-98. Seo Bot. 
Ztg., lvi, (1898) 2 te Abth., p. 262. 
X Ber. Deutsch. Bot. Gesell., xvi. (1898) pp. 164-9 (1 pi.). 
§ Flora, lxxxv. (1898) pp. 362-7. Cf. this Journal, 1898, p. 551. 
|| Comptes Rendus, cxxvii. (1898) pp. 282-3. Cf. this Journal, 1892, p. 632. 
