ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 99 



Lime-dissolving AlgaB.* — E. Bachmann has examined a quantity 

 of limestone deposits at Plauen, near Meiringen, on the north shore of 

 the Walensee, and in Austrian Croatia, all of which are washed with 

 flowing water. On this limestone he finds a series of Cyanophyce^ 

 which are remarkable for their power of dissolving Hme. At Plauen 

 the algae are mostly overgrown with epi- and endolithic lime-lichens. 

 But there are also many patches, 1 sq. m. in size, strewn with small 

 black dots, consisting of colonies of GImocapsa. Each colony inhabits 

 the lower end of a funnel-shaped cavity, while the upper end serves as a 

 water reservoir. In contrast to the lime-lichens, the rock-dwelling 

 Schizophycea3 work downwards rather than horizontally. The dissolving 

 of the lime cannot, as Nadson believes, take place through excretion of 

 lime oxalate, because in that case the origin of the cavities could not be 

 explained. The author considers it more probable that the algte secrete 

 an acid, which forms a soluble salt with lime. This is then at once 

 washed away by the water. Thus an equivalent quantity of CO^ is set 

 free, which combines with the neutral calcium carbonate to form a 

 bicarbonate which is soluble in water ; and so the work of solution 

 continues. In the locality near Meiringen the following species were 

 found : — GI(BOcaj)sa atratn, Scytonema mijochrona, Ppjitalonema crus- 

 taceum, Foreliella perforans, and Gongrosira cocUofoUa. At the Tobel- 

 schlucht were found Ghroococcus sp., Aphanothece caldariorum (?), in 

 addition to those already enumerated. These algse dissolve the lime 

 better than the algte of the Plauen limestone. The algal limestone is 

 distinguished from the lichen limestone by its greater degree of porosity. 

 The alg£e are therefore remarkable for possessing a greater power of 

 dissolving the matrix than the lichens are. 



Alg-al Vegetation on the Rock Walls of the Elbe Sandstone 

 Mountains.! — B. Schorler describes the algal vegetation on the moist 

 rocks of Saxon Switzerland, and the ecological factors bearing on it. 

 The subject is discussed from the points of view of plant geography, 

 distribution of species, and the causes of it. Tlie following associations 

 are examined : Stephanosphteretnm, Cladophoretum, Bacillariacetum, 

 Chromulinetum, Glceocapsetum, Gloeocystetum, Mesotienietum, and 

 Pleurococcetum. 



Bavarian Fresh-water Alg8B.| — P. E. Kaiser publishes an addition 

 to his first list of the algae of the Traunstein and the Chiemgau. The 

 number of species and varieties is now 108. No new species are de- 

 scribed, but critical notes are appended to the enumeration of the diatoms. 



Gonium.§ — R. A. Harper writes on the structure and development 

 of the colony in Gonium. His paper is primarily a study of the space 



* Ber. Deutsch. Bot. Gesell., xxxiii. (1915) pp. 45-57 (1 pi.). See also Bot. 

 Centralb., cxxix. (1915) p. 492. 



t Abh. Natw. Ges. Isis, Dresden (1914) pp. 3-27. See also Bot. Centralb!., cxxix. 

 (1915) p. 466. 



X Mitt. Bayr. Bot. Gesell. Erf. Heim. Flora, iii. (1914) pp. 151-9. See also 

 Bot. Centralbl., cxxix. (1915) p. 566. 



§ Amer. Micr. Soc. Trans., xxxi. (1912) pp. 65-82 (1 pi. and figs.). See also Bot. 

 Centralbl., cxxix. (1915) p. 407. 



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