596 SUMMARY OF CURRENT RESEARCHES RELATING TO 



He contributed also to Eugler and Prantl's Natiiiiichen Pflanzen- 

 familien the section which deals with Phsophyce^. 



BiANCHi, F. — Ricerche su un laghetto Alpino (II Lago Deglio). (Researches on 

 a small Alpine lake, Lake Deglio.) 



[Eninnerates the species of plankton and neritic benthos found in this small 

 lake in the province of Como, together with physiographical data.] 



Eevista Geografica Ital., xiii. fasc. 4 (1906). 



Largaiolli, v. — La varieta oculata del Glenodinium pulvisculus (Ehr.) Stein. 

 (The oculate variety of G. pulviscuhis.) 



[A description with figures of this new variety oculatuni, which causes the 

 particular coloration of Lake Tovel, in Trentino.] 



Nuov. Notar., xviii. (1907) pp. 169-73. 



M A z z A, A. — Saggio di Algologia oceanica. (Marine algology.) 



[A continuation, which treats of several genera of Florideae.] 



Tom. cit., pp. 126-52. 



SvEDELius, N. — TJber einen Fall von Symbiose zwischen Zoochlorellen und einer 

 marinen Hydroide. (On a case of symbiosis between Zoochlorella and a marine 

 hydroid.) 



[The first record of this phenomenon in a marine hydroid, the only case 

 known being with the fresh-water species H. viridis.'] 



Svensk. Bot. Tidskrift., i. (1907) pp 32-50. 



Tebry, W. A. — Causes of Variation in Colour in some Red Algae. 



[The author describes some instances of this as occurring after desiccation 

 in Dasya elegans. Specimens from different localities dry diSerent 

 colours, and these differences are constant for a given locality. This is 

 attributed to the presence of different minerals in solution in the water at 

 the respective stations.] Bhodora, ix. (1907)- pp. 90-1. 



Fungi. 



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



Study of Synchytrium.* — Walter Rytz has made a biological and 

 morphological study of a number of species of this genus. He based his 

 Vfovk on Si/nchytrium aureum, which has been recorded on 125 different 

 host-plants. Rytz took several of these hosts in separate locaHties on which 

 the fungus was most richly developed and then co-related the plants in 

 the neighbourhood that were living in the same conditions and that also 

 had Synchytrium galls on their leaves, though to a somewhat less extent. 

 He thus found that S. aureum, which had its chief habitat on Lysimachia 

 nummidaria, also attacked in a less degree species of Potentilla, Valeriana, 

 Hypericum, Epilohium, and Myosotis. The place where these plants grew 

 was liable at times to \)Q overflooded, and at all times was damp. The 

 fungus was formed towards the end of September. 



In a quite different locality, where the plants were constantly washed 

 with fresh water from a mountain stream, he found plants of Saxifraga 

 aizoides very badly infected. The neighbouring plants that had similar 

 galls were Saxifraga steUaris, S. moschata, and S. androsacea, with species 

 of Androsace, Hutchinsia, Leontodon, Viola, and Ranunculus. This form 

 he designates as Synchytrium Saxifraga,. In a similar manner he 

 differentiates S. infestans, mainly on Leguminosge, S. Galii, S. vulgatum, 

 and S. Wurthii. He thus considers the large species S. aureum rather a 

 collective form which has become more or less specialised according to 



* Centralbl. Bakt., xviii. (1907) pp. 635-55, 799-825 (1 pi. and 10 figs.). 



