ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 279 



Thallophyta. 

 Algae. 



(By Mrs. E. S. Gepp.) 



Symbiosis of Bacteria and Flagellates with Cyanophycese.* — 

 A. Tascher follows up the work of Bader on the symbiosis of a bacterium, 

 Ghlbronium, with a cyanophyceous organism, by describing similar cases. 

 In two of these, lower blue-green alga? are associated with a bacterium, 

 respectively Bacterium sp. and Spirillum sp. In the third case the 

 association is with a monad. The author proposes for such associations 

 the term Syncyanosis. The symbiosis does not go so far as that one of 

 the symbiohts loses its independence. The algae were found in quantity 

 in an independent state. Also in the case of the bacteriosyncyanosis, the 

 death of the bacterium did not prevent a large reproduction of the blue- 

 green algae. The usefulness of the symbiosis, according to the author, is, 

 for the bacterium or the monad, in the production of carbonic acid by 

 the assimilating organism ; for the algae, perhaps in the absorption of 

 decay products of the mucilaginous sheath. Cases of syncyanosis do not 

 appear to the author to be radically different from the well-known 

 associations of higher Cyanophyceae with gelatinoid algae. The author 

 finally discusses two new associations of algae with one another ; an 

 Anabmna with a small net-forming Chlorococcacea, and a green alga with 

 a Charnaesiphonacea. 



Water-blooms.f — R. Kolkwitz discusses water-blooms, and insists on 

 the importance of quantitative examination. He records a number of 

 quantitative results. Oscillatoria Agardhii was found in August, 1911, 

 by the author in the Lietzensee in quantity about 20,000 filaments to 

 1 c.cm. of ladled-out water ; in February and March, on the other hand, 

 he found only 15-20 filaments in 1 c.cm. He also gives informatioii 

 about marine water-bloom. The development of water-bloom is depen- 

 dent on temperature, and shows also a connexion with the richness of 

 the water in organic substances. Those lakes which have yellow water, 

 containing much h tunic constituents and substances with a nutritive 

 value, such as the Havelseen, the Miiggelsee and others, are much 

 richer in plankton and water-bloom than the lakes with blue-green 

 water, which is poor in organic substances, such as mountain lakes, the 

 Lake of Geneva, etc. 



Water-bloom of G-onium pectorale.J — D. Piumecke had under 

 observation a small aquarium in the open (1'25 m. x 1*00 m. x 0*40 m. 

 deep), which contained several cm. of mud, and the water of which was 



* Ber. Deutsch. Bot. Gesell., xxxii. (1914) p. 339. See also Bot. Centralbl., 

 cxxviii. (1915) p. 50. 



t Bot. Jabrb. Festb., 1914, pp. 349-56. See also Bot. Centralbl., cxxviii 

 (1914) p. 502. 



J Ber. Deutscb. Bot. Gesell., xxxii. (1914) pp. 131-6. See also Bot. Centralbl., 

 cxxviii. (1914) p. 503. 



