76 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



Thallophyta. 



Algae. 

 (By Mrs. E. S. Gepp.) 



Aberrant Forms of Marine Algae produced artificially.*— C. Tecbet 

 publishes some observations upon some aberrant forms of marine algae 

 obtained by artificial cultivation. The experiments were not carried out 

 systematically enough to allow general conclusions to be drawn. They 

 show that the plants responded to stimuli in various ways ; and the only 

 general deduction is that in water of less salinity the plants assume a 

 more quick-grown and less branched form than in more strongly saline 

 solutions. The nutritive solution employed consisted of the following 

 ingredients : — calcium nitrate 2 p.c. ; potassium phosphate • 2 p.c. : 

 magnesium sulphate • 2 p.c, with a trace of ferric chloride ; sea-water 

 97*6 p.c. Every five months four or five drops of the above were added 

 to the cultures and slowly and carefully stirred in with a glass rod. The 

 jars used for the cultures were of glass and cylindrical, about 10 in. high 

 and 8 in. diameter. The plants experimented with were Halimeda Tuna, 

 Udotea Desfontainii, Valonia macrophysa, Acetabularm mediterranean 

 Dasycladus clavceformis, Antith amnion Phimula, Callithamnion sp., PoUj- 

 siphonia, Ectocarpus. The results obtained are shown in a series of 

 figures. 



Light-perception in Algae. J— R. H. France publishes a paper on 

 the light-sensitive organs of algae, in which he expresses his views as 

 to the presence of an inner psychical faculty in plants ; tells of his own 

 experiments with Euglma viridis and Polyioma uvella ; treats of the 

 pigment-spot or eye-spot in these algae ; and constructs his theories as 

 to the physiology of stimulation in plants. 



Biology of Crater-lakes in South Italy. J — A. Forti and A. Trotter 

 publish an account of the flora and fauna of the two crater-lakes of 

 Mt. Vulture, situated in southern Italy, between the province of 

 Basilicata and the Principato Ulteriore. These Laghi di Monticchio 

 are situated at an altitude of 2160 ft. above sea-level, and are about 

 100 ft. deep. The physical geography and the general aspects of the 

 biology of the lakes are discussed by A. Trotter. The analysis of the 

 microscopic material, and the preparation of the principal deductions 

 therefrom, are the work of A. Forti. The latter detected forty-one algae 

 and twenty-five animals in the plankton gatherings, and has arranged 

 these in a series of tables to illustrate his arguments. Further, he dis- 

 cusses each of the species in a separate paragraph by itself. In the 

 deposit from the bottom of the lakes he found seventy-nine species of 

 diatoms. 



Algae of Lampedusa and Linosa.§ — S. Sommier publishes a 

 modernised flora of the Pelagian Islands, Lampedusa, Linosa, and 



* Nuov. Notar., xix. (1908) pp. 171-84 (figs.), 



t Stuttgart: Kosmos, 1908,80 pp. (1 pi. and figs.). 



X Annalidi Bot., vii. (1908) Suppl. Ill pp. (3 pis.). 



§ Firenze : Stabilimento Pellas, 1908, 345 pp. 



