828 SUMMARY OF CURRENT RESEARCHES RELATING TO 



deprived of carbonic acid where no direct assimilation could take 

 place. Malic acid contains a larger proportion of oxygen than tho 

 carbohydrates, and tho transformation must therefore be accompanied 

 by evolution of this gas. 



B. CRYPTOGAMIA. 



Underground Algae and Fungi.* — Herr A. Schneider gives an 

 account of the vegetable organisms found in coal-pits, salt-mines, and 

 ore-mines in different parts of Germany. They comprise rhizoniorphs, 

 Mucorini, Plcosporoas, diatoms, Oscillariacea), palinella-likc colonics, 

 micrococci, spirilla, &c. 



Cryptogamia Vascularia. 



Bursting of the Sporangium of Ferns.f — Herr J. Schrodt 

 explains this phenomenon as follows : — The bursting of the sporangium, 

 and the twisting of the freo end of the annulus to the extent of 360°, 

 are caused solely by the pressure of the atmosphere, which acts on 

 tho cells of the annulus through transpiration and evaporation. 

 When this process is completed, the thin semi-cylindrical membrane 

 of the sporangium very quickly attains tho degree of dryness at which 

 it becomes permeable to air under the pressure of one atmosphere. 

 The air therefore enters the cells suddenly ; and these in conse- 

 quence assume nearly their original volume. But the air which enters 

 in this way has not the tension of the atmosphere ; since, in consequence 

 of its entering tho cell-cavity, the force of external pressuro is so 

 much diminished that it is no longer able to overcome the resistance 

 of the air-dry membrane. The definite condition of the annulus 

 results from the shortening of the thin membrane and the rarefaction 

 of tho air which is still present in the cells. 



Fructification of Calamodendron4 — M. B. Eenaidt has carefully 

 examined the structure of a large number of the spikes of Calamo- 

 dendron, and has come to the conclusion, from the complicated 

 structure of the sacs contained in them and that of the reproductive 

 bodies which they inclose, that they must be regarded as pollen-sacs 

 and pollen-grains, and that the Calamodcndra are therefore shown to 

 be flowering plants by the structure, not only of their roots and stems, 

 but also of their fructification. 



Development of Lycopodiacese.§ — Dr. M. Treub has continued 

 his researches on this subject, following up his previous observations 

 with an examination of the development of Lycopodium Phlegm aria. 

 The germination of the spores appears to be slow ; but the oophore 

 is capable of various modes of asexual multiplication ; indeed it 



* Programm der K. Rcalschule zu Berlin, 32 pp. (2 pis.), 1S85. See Bot. 

 Oenlralbl., xxvi. (1886) p. 33. 



f Ber. Deulsch. Bot. Gesell., iii. (18SC) pp. 396-405 (4 figs.). Cf. this 

 Journal, ante, p. 479. 



% Comptes Rendus, cii. (1880) pp. C34-7. 



§ Ami. Jurd. Bot. Buitenzorg, v. (1SS5) (20 pis.) See Prof. F. O. Bower in 

 Nature, xxxiv. (1880) p. 115. Cf. this Journal, v. (1885) p. 277. 



