616 SUMMARY OF CURRENT RESEARCHES RELATING TO 



which mostly belong to the Pseudo-Raphidiete, and explains how this 

 snb-faniily has become adapted to inhabit Alpine streams. 



Bacillariaceae from Nyassa Land.* — 0. Muller publishes his fourth 

 and last report on the collection of Bacillariacere obtained by the Nyassa- 

 See and Kinga-Gebirg expedition. He treats of the Naviculinae, Fragi- 

 larinse and Eunotiinse, comprising 'lb genera and 265 species, etc., of 

 which 38 are new. The total for Nyassa Land and the surrounding 

 region is thus raised to 40 genera and 509 species, of which 125 are new. 



Calcareous Phosphates composed of Diatoms. f — L. Cayeux describes 

 an interesting investigation of a fragment of limestone brought from the 

 banks of the Senegal river at Daoulalel by M. Chadeau. The formation 

 is clearly Lower Eocene, hitherto unknown either in Senegal or through- 

 out the centre of Africa. The fragment of limestone consists of phos- 

 phorus elements of irregular size and shape, and are of two sorts ; one is 

 composed of bone matter and the other of broken scraps of diatoms. 

 Among the rare specimens which are whole and recognizable was seen 

 Triceratium and Coscinodiscus. The result of this investigation is inte- 

 resting to geologists, botanists and to the commercial world, inasmuch as 

 the discovery of tripoli in Senegal may lead to its being found anywhere 

 between that region and Tunis in sufficient quantity for practical use. 



Characium.:): — F. D. Lambert describes two new species of Characium, 

 G. gracilipes and G. cylindricum, which were found growing on Branchi- 

 pus vernalis in a small pool at Medford, Mass. They were both identified 

 by F. S. Collins and distributed as Nos. 1261) and 1270 in the Phyc. 

 Bor.-Amer. The author gives diagnoses and descriptions. He also 

 adds a few remarks on Dactylococcus Hookeri and D. de Baryanum, 

 which Collins regards as belonging to Characium. G. gracilipes and 

 G. cylindricum are hosts of a fungus, of which the author figures two 

 stages, promising further notes on the subject at a later date. 



Coleochsete.§ — F. 1). Lambert describes and figures an unattached 

 zoosporic form of Goleochsete, found in a small pond in Massachusetts, 

 which he takes to be the dwarf zoosporic plants of G. scutata described 

 by Pringsheim. The present observations confirm those of Pringsheim. 

 These zoosporic plants form an independent phase in the life-history of 

 the alga, but their existence has not always been recognized by authors, 

 who have cast doubt on Pringsheim's statements. Details and figures of 

 the development of this form are given in the present paper. 



Dasycladus clavseformis. || — W. Figdor gives the result of his ex- 

 periments on Dasycladus clavseformis as regards regeneration. He tried 

 to force the plant to restore a lost vegetative growing-point, and was 

 successful in nearly all cases. His attempts to bring about regeneration 

 of the basal end of the plant failed in every case, and he found that in 

 no plant were the rhizoids formed again after having been removed. 



* Eugler's Bot. Jahrb., xlv. (1910) pp. 69-122 (2 pis. and figs.). 



t Comptes Rendus, cli. (1910) pp. 108-10. 



% Tufts College Studies, iii. No. 1 (1910) pp. 1-11 (pL). 



§ Tom. cit., pp. 61-8 (pi.). 



II Ber.Deutsch. Bot. Gesell., xxviii. (1910) pp. 224-7. 



