574 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
of Gomphonema acuminatum without a stalk, and associated in a spiral 
resembling Meridian circulars \ the protoplasm yellow-brown. A small 
species of Synedra multiplied within an oval transparent envelope, in 
which the frustules lay side by side. 
Changes of Form of Seeletonema costatum.* — Herr G. Karsten has 
studied the movements of this diatom, belonging to the Coscinodisceae, a 
plankton-alga associated in chains, and concludes that the multiplication 
and development are regulatad by internal forces dependent on external 
conditions. The propagation takes place only half as rapidly in flowing 
as in standing water. 
Nostoc punctiforme. — Following out his observations on the de- 
velopment of this organism, M. R, Bouilhac j’ has established that it is a 
plant which can develop in absolute darkness if it be supplied with an 
organic substance such as glucose. It can develop both like a green 
plant by decomposing carbon dioxide, and as a non-clilorophyllous plant 
by assimilating an organic substance. 
In another paper MM. A. Etard and R. Bouilhac J state that this 
organism preserves, in the dark, the power of forming chlorophyll. 
/3. Schizomycetes. 
Bacterial Diseases of Plants. — Prof. J. C. Arthur § summarises the re- 
ports in the Bulletins of the various experimental stations in the United 
States, respecting diseases of cultivated crops and fruit-trees due to 
the attacks of Schizomycetes. A new bacterial disease of sweet-corn is 
described, attacking the plant chiefly at the time of flowering, clogging 
the fibrovascular bundles of the stem. The olive-knot or tuberculosis 
of the olive is ascribed to the attacks of Bacillus Olese. 
Sig. F. Cavara || describes the following bacterial diseases of the 
grape-vine : — Tuberculosis, produced by Bacillus Ampelopsorse ; necrosis, 
by B. cubonianus ; also necrosis of the mulberry, due to two different 
Schizomycetes, one of them resembling B vitivorus and identical with 
B. cubonianus , the other a new chromogenous species, B. Mori carneus ; 
tuberculosis of the peach, caused by an undescribed species, Clostridium 
Persicse tuberculosis sp. n. 
According to Prof. B. D. Halsted,!" bacteriosis of the “bush-bean” 
is due to the attacks of Bacillus Phaseoli. 
Herr W. Schostakowitsch ** describes the remarkable changes pro- 
duced in Mucor proliferus by a bacterium, rendering the species almost 
unrecognisable. 
Pathogenic Streptotlirix in Sputum. tt — Herr Rullmann found a 
pathogenic streptothrix in sputum, supposed to be derived from a lesion 
near the root of the lung. The fungus stained easily, and was not 
* Wissensch. Meeresunters., iii., Heft 2, Kiel, 1898. See Bot. Ztg., lvi. (1S98) 
2 te Abt., p. 203. 
t Comptes Rendus, cxxvi. (1898) pp. 1583-6. Cf. this Journal, ante, p. 225. 
j Op. cit., cxxvii. (1898) pp. 119—21. § Bot. Gazette, xxxv. (1898) pp. 461-3. 
|| Le staz. sperim. agrar. Ital., xxx. (1897) pp. 482-509. See Hedwigia, xxxvii. 
(1898) Rep., p. 100. 1 Bull. Torrey Bot. Club, xxv. (1898) pp. 329-31 (1 fig.). 
** Ber. Deutsch. Bot. Gesell., xvi. (1898) pp. 91-7 (1 pi.). 
ft Munch. Med. Woehenschr., July 19, 1898. See Brit. Med. Journ., 1898, ii. 
Epil. 180. 
