242 SUMMARY OF CURRENT RESEARCHES RELATING TO 



interrupted and is therefore incomplete, but is published in the hope 

 of being useful to future students of the district. The number of 

 species recorded is fifty-nine, 



Algse from;Beng'asi.* — G. B. de Toni and A. Forti issue a catalogue 

 of fresh-water algje collected in the region of Bengasi, in Tripoli, by 

 Vito Zanon. Five of the species are new records for the African 

 continent. Seventy-one species are recorded from Giuliana and thirty- 

 two from Bengasi. Notes are appended to some of the records. 



Oceanic Alg'ology.f — A, Mazza continues his studies of marine algse, 

 giving descriptions of the structure of certain Squamariacese — Rhodo- 

 dermis Van-Heurckii and of three species of Hildenbrandtia. Passing 

 on to the Corallinace^e, he gives a scheme of the genera arranged in the 

 form of a key, and then begins the description of their structure. In 

 the present part he treats of Schmitzidla (1 sp.), Chsetolithon (1 sp.), 

 Epilithon (1 sp.), SporoUtho7i (2 sp.), Litlioihamnion (6 sp.). 



Fungi. 

 (By A. LoRRAiN Smith, F.L.S.) 



Origin of Spongospora.| — Gr. R. Lyman and J. E. Rogers have 

 collected information as to the country of origin of this potato disease. 

 It is very wide-spread in Europe, and within the last three or four 

 years it has appeared in the United States and in Canada. 



It is considered to be a very old disease, as the union between host 

 and parasite is extremely intimate, and the destruction of the host tissues 

 very slow. Specimens of diseased potatoes have recently been discovered 

 in Peru from the limits of potato production, where European materials 

 could hardly have been present, and the supposition is that both host 

 and parasite are indigenous in that locality. The disease there is not 

 severe, and the spores are smaller than in European or American tubers. 



Control of Chrysophlyctis endobiotica.§ — E. Schaffint and Gr. Voss 

 have been experimenting with measures to combat this disease in Germany. 

 They give a list of the substances employed to destroy the fungus in 

 the soil. None of them gave great satisfaction ; the best results were 

 obtained with chromium acid carbonate. The experiments are to be 

 repeated. 



Many different varieties of potato were grown, and it was found 

 that a number were immune from the disease ; others were slightly 

 attacked, and yet others became very badly diseased. 



The vitality of the spores in the soil also received attention. 

 Potatoes were grown on soil that had been diseased in 1907 and has not 



* Atti Real. 1st. Veneto Sci. Lett. Art., Ixxvi. (1916). See also Nuov.Notar. 

 xxviii. (1917) pp. 128-9. 



t Nuov. Notar., xxviii. (1917) pp. 70-110. 



J Science, xlii. (1916) pp. 960-41. See also Bull. Agric. Intell. Rome, vii. (1916 

 pp. 1033-4. 



§ Zeitschr. Pflanzenkr., xxvi. (1016) pp. 183-92. 



