342 SUMMARY OF CURRENT RESEARCHES RELATING TO 



length of time which is required to produce complementary chromatic 

 adaptation depends on the strength of the light. Chromophylls have 

 the power of photographing the colours complementarily. The speed 

 of the process shows that it is here a question of actual change of colour 

 of the old cells, not the formation of new cells with differently coloured 

 chromophylls. In the macroscopic experiments only two main com- 

 plementary colours are to be seen, green and red, blue-green and brown- 

 yellow, not the various intermediate shades. Complementary colour- 

 change depends on the change of structure of the chromophylls. 

 Finally, the author answers tbe questions raised by Oltmanns on this 

 subject in the second volume of his " Morpholosde und Physiologie der 

 Algen," p. 196. 



Holtz, L. — Neue Fundorte von Characeenauf der Insel Sizilien, von Dr. Ross. (New 

 localities for Characese in Sicily, discovered by Dr. Ross.) 



[A list of 14 species and varieties, containing one new variety, pseudo- 

 spinosissima, of Chara crinita Wallr. A detailed description is given.] 



Nuov. Notar., xvii. (1906) pp. 57-60. 



Keisslee, K. v. — Beitrag zur Kenntnis des Planktons einiger kleinerer Seen in 

 Karnten. (Contribution to a knowledge of the plankton of some rather small 

 lakes in Carinthia.) 



[Describes the plankton of five small lakes, and makes remarks on the 

 distribution of the species here recorded.] 



Oest. Bot. Zeit., lvi. (1906) pp. 53-60. 



Mazza, A. — Saggio di Algologia oceanica. (Essay on oceanic algology.) 



[A continuation, which includes Caulacanthus, Gelidium, Pterocladia, and 

 Suhria.'] Nuov. Not., xvii. (1906) pp. 41-56. 



Migcla, W. — Thome's Flora von Deutschland. V. Kryptogamen. (Flora of 

 Germany. Cryptogams.) 



[Diatomacese, continued. Diploneis — Navicula.] 



Gera: Zezschwitz, 1906, lief. 26, pp. 225-56 (5 pis.). 

 Setchell, W. A. — Regeneration among Kelps. 



Univ. Californian Publications, ii. (1905) pp. 139-68 (3 pis.). 



Stock m aye e, S. — Kleiner Beitrag zur Kenntnis der Susswasseralgenfiora Spitz- 

 bergens. (Small contribution to the freshwater algal flora of Spitzbergen.) 

 [A list of 29 species, of which one, Etmstrum Wiesneri, is new.] 



Oest. Bot. Zeit, lvi. (1906) pp. 47-53 (7 figs, in text). 



Fungi. 



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



Urophlyctis Alfalfae.* — E. S. Salmon detected this fungus on the 

 roots of Lucerne from Heme Bay, where it had caused the death of a 

 good many plants. The fungus, one of the Chytridineas, forms gall-like 

 structures from the hypertrophied tissue of the host. These galls con- 

 tain a number of minute chambers which are filled with the brownish 

 spores. The disease was first observed in Ecuador. This is the first 

 record of the disease in Britain. 



Morphology and Development of Empusa.f — Edgar W. Olive 

 begins with an historical sketch of the investigations that have already 



• Gard. Chron., xxxix. (1906) p. 122. 



t Bot. Gazette, xli. (1906) pp. 192-208 (2 pis.). 



