8G SUMMARY OF CURRENT RESEARCHES RELATING TO 



Sebille, E. — Nouvelles observations sur Gastero^rimmia poecilostoma (Cardot et 

 Sebille). 



[Description of tlio male plant, and distribution of this moss-species in 

 Dauphine.j Rev. Bryol , xxx. (1903) pp. 105-0. 



The riot, J. — Brachythecium populeum (Hedw.) Br. Eur. var Levieri, var. nov. 

 [Description of a moss gathered at Uormio.] 



Bull. Soc. But. Ital, 1903, p. 220. 



Thallophyta. 

 Algae. 



Polymorphism of Algse.* — A. Hansgirg adds a final note to his 

 work on this subject, pointing out the inevitable necessity for a thorough 

 reform in the systematic classification of algae, and maintains that the 

 study of " pure cultures " of algae, advocated by Klebs as a necessary 

 preliminary to such reform, will only lead to error. He gives a list of 

 papers bearing on this subject, which have appeared since the publication 

 of his paper, ' On the Polymorphism of Alga?,' in 1893. 



Fossil Algae.f — P. Fliche records some additions to the genera of 

 fossil algae, which, from their resemblance to modern genera, he names 

 Chordites, Lomentarites, and Cystoseirites Sternb. (emend.). Each is 

 represented by a single species. Lomentarites was found in the Gres 

 Vigarre, at Merviller-Vacqueville, the other in the Muschelk.-superieure, 

 at Chauffontaine and Sainte-Anne, near Luneville. They were all very 

 abundantly represented. Four other species from the Muschelkalk have 

 been named Algae ites, since the author cannot with certainty place them 

 near any existing genus, though he has no doubt as to their algal nature. 



B. Renault publishes a note on the algae which form " Boghead," 

 in which he states that this formation in the northern hemisphere is 

 characterised by the presence of Pila ; Reinsehia occurs everywhere in 

 the southern hemisphere ; Thylax britannicus is the principal constituent 

 of British Boghead, and Cladiscothallus that of the Moscow beds. Every 

 important stratum can be recognised by the algae of which it is formed. 



Algae in Public Water-supplies.:}:— G.T.Moore reports on the con- 

 tamination of reservoirs and cress-beds by fresh-water algae. Spirogyra 

 uives considerable trouble in a mechanical way by smothering the young 

 water-cress plants, and it also forms a thick heavy mat over the surface 

 of the water, thus preventing the growth of even the older plants. The 

 Schizophyceae are very commonly the cause of pollution in drinking- 

 water, especially the genera Olathrocystis, Anabana which produces a 

 polluting oil, and Oscillatoria. Diatomaceae, notably the genus Aste- 

 rionella, play a prominent part in the pollution of water, as also members 

 of the group Syngeneticeae. The author mentions as methods of pre- 

 vention of such pollution : the covering over of reservoirs, since light is 

 favourable to algal growth ; the keeping of both source of supply and 

 reservoir as free as possible from organic matter ; and the aeration of 

 water by pumping, fountains, or some sort of spraying apparatus. The 



* Beibl. Bot. Jahrb. xxxii. No. 72 (1903) pp. 1-3. 



t Comptes Rendiis, exxxvi. (1903) pp. 827-9, 1340-3 (6 figs.). 



t Year Book Dept. Agricult. U.S.A. (1902) pp. 175-80. 



