8 Alffae. 



to' 



Hanson, E. K., Phvcoer^^thrin, the pigment of the Red 

 Algae, (Proc. Chem. Soc. XXV. p. 117 — 118: 1909). also: Obser- 

 vations on Phy coery thrin, the red pigment of Deep- 

 Water Algae. (New Phytologist, VIII. p. 337—344. 1 plate. 1909.) 



Ceramiutn rubrum, is the only alga that gave a fair yield of the 

 pigment and even that has not yielded enough for an extended 

 Chemical investigation of the pure pigment. The water extract from 

 fresh material killed with Chloroform was concentrated in vacuo at 

 38^ C and the phycoerythrin separated by fractional precipitation 

 with alcohol. It is a colloid, easily passing into an irreversible gel, 

 and could not be prepared free of mineral matter. Its nitrogen con- 

 tent is too low for a proteid and it does not give the Biuret reaction. 

 A summary of its reactions is given. Pepsin is without action upon 

 it but trypsin decolorises it and seems to give a trace of leucin. 



A photograph of the absorption spectrum is given which con- 

 firms Schütt's measurements and a special study was made of the 

 brilliant orange fluorescence. This was photographed and shows two 

 bands at l 656 — 630 and l 600 — 570, being approximately the 

 location of the absorption bands I and III of Chlorophj'^ll. As this 

 fluorescence is produced when only pure blue light reaches the 

 pigment, the view of its great importance as a link in enabling 

 Chlorophyll to assimilate in the blue light of deep-water finds strong 

 Support. J. J. Blackman. 



Paulsen, O., Plankton in vestigations in the waters round 

 Iceland and in the North Atlantic in 190 4. (Meddelelser 

 fra Kommissionen for Havundersogelser. Ser. Plankton I. 8. 57 pp. 

 in 40. 9 figs. Köbenhavn 1909.) 



Of this paper the following may be quoted as being of botanical 

 interest. 



The neritic plankton of South Iceland is characterized by 

 the diatom Asterionella japonica. With the "Irminger Current" this 

 plankton drifts along the west coast of Iceland, generally keeping 

 outside (to the west) of the real coastal plankton, dominated by 

 Thalassiosira. 



Both at south and west Iceland the spring coastal plankton 

 is succeeded in the summer by Dinoflagellate plankton, but in the 

 autumn there is a faint second diatom maximum, together with the 

 Dinoßagellates. 



At the north coast there are three maxima of diatoms, of which 

 the second (in July and August) may be mixed with Diuoflagellates. 

 The third maximum, in October is, like the spring maximum, of 

 dififerent nature at the western and eastern part of the coast, the 

 plankton at the western part of the north coast being as a whole 

 more like the plankton of the west coast, that at the eastern part 

 being colder and more oceanic. 



The distribution of the Ceratium-species , dominating in the 

 plankton is described and charted. C. tripos is mostly found at the 

 south coast oxiXy. In the plankton, which drifts north wards along 

 the west coast, it is succeeded by C. lineatwn, which according to 

 Lohmann is said to be able to arise from C. tripos. The author 

 suggests that this is the case here, the transition taking place where 

 the water grows cooler. C. lineatum has a maximum at the western 

 north coast, where it seems to copulate. 



Ceratium furca and intermediuyn are southern species, C. arcti_ 



