386 SUMMARY OF CURRENT RESEARCHES RELATING TO 



formalin and water (1 : 100), 10 litres of the solution being applied 

 per square metre. The watering was done about two weeks before 

 healthy tubers were planted. The plants on all the plots grew normally 

 and vigorously, and the potatoes were lifted in September. It was then 

 found that on the disinfected plots there were no diseased tubers ; on 

 all untreated plots there was more or less of disease. Ericksson desires 

 that experiments should be tried in England, as it seems probable 

 that this destructive disease might be eradicated in gardens where 

 rotation of crops for a lengthened period is impossible. 



E. J. Butler and A. Hafiz Khan * publish some new diseases that 

 have been found attacking sugar-cane in India. They are due to various 

 fungi belonging to the Fungi Imperfecti : Cephalosporin,™ sacchari sp. n., 

 which they call "wilt"; Hendersonia sacchari, which causes a "collar 

 rot"; and Helminthosporium sacchari sp. n., which gives rise to what 

 they term " Helminthosporiose." In the latter case it is the leaver 

 that suffer, red spots being produced which run together and foriL 

 streaks. 



Lichens. 

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



Zoospores of Lichen Gonidia.t — The formation of zoospores in 

 gonidia which were isolated from the Physcia thallus was observed and 

 described by Famincyn and Baranetzky in 1867. In more recent 

 times their results were criticized by Beijerinck and by Chodat, the 

 latter questioning the purity of the cultures. Famincyn replies to these 

 critics in reaffirming the accuracy of their observations, and cites the 

 drawings made by them of algal cells forming zoospores that still had 

 lichen hyphse attached to them. He insists on the great carefulness of 

 the methods adopted in tbeir experiments which were repeated by them 

 to avoid all chance of error. 



Swedish Lichens.:}: — F. Erichsen has published a critical list of the 

 lichens of the peninsula of Kullen, on the west coast of Sweden. He de- 

 scribes the topography of the district, the character of the rocks, soil, and 

 trees on which the lichens grew. There is in such a locality a great 

 variety of lichen vegetation, both maritime and inland, saxicolous and 

 corticolous. On the higher plateau there are moors consisting of Calluna, 

 etc. The woods consist mainly of oaks, beeches, elms, and alders, and 

 on all of them a rich lichen vegetation found place. Lists are given of 

 the species that were found on these trees as also on the various conifers. 

 There was very little old wood, as stone walls took the place of palings, 

 but a fair number of wood species were found on the stumps. 



* Mem. Dept. Agric. India, vi. 6 (1913) pp. 181-208 (6 pis.). See also Bot. 

 Ceutralbl., cxxv. (1914) p. 670. 



t Ber. Deutsch. Bot. Gesell., xxxii. (1914) pp. 218-22. • 

 J Verh. Naturw. Ver. Hamburg, xxi. (1913) pp. 25-93. 



