«S0 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Research," wherein is given a summary of the main results of modern 

 marine biological investigation. Part I. treats of the exploration of the 

 sea, and contains a description of oceanographical apparatus, the con- 

 stitution of the sea-bottom in northern waters, the living organisms — 

 the plankton, benthos and nekton. Part II. is concerned with quanti- 

 tative investigations, the estimation of the number of species, the distri- 

 bution of the forms, their economic importance in relation to the fisheries. 

 Part III. tells of the metabolism of the sea, the physiology of the 

 organisms, the mystery of migration, the action of bacteria, the circula- 

 tion of nitrogen. A bibliography is appended. 



Regeneration in Myrionema.* — F. Tobler describes and figures the 

 method of regeneration in Myrionema. M. vulgare, one of the commonest 

 Ectocarpacege of the North Sea, forms remarkable brown spots on the 

 upper parts of the stem of Laminaria where there is an absence of other 

 algas. In August 1907, in Trondhjem Fjord, in a strong sea-current, 

 where only Laminaria digitata abounded at about 1-2 metres below 

 low water-mark, the Laminaria stems were found to be free from all 

 epiphytes except M. vulgare ; and this showed signs of the action of the 

 strong current. The tufts lacked the normal character of assimilators, 

 hair-threads and (plurilocular) sporangia juxtaposed. The sporangia 

 were absent, the hair-filaments rare. And the author describes in detail 

 the anomalous appearance of the assimilators and the process of regenera- 

 tion which was going on in some of them. 



Biology of Polysiphonia fastigiata.f — Gr. Tobler- Wolff discusses 

 the biology of Folysiphonia fastigiata, and states that in the North Sea 

 it is only known to occur on Ascophyllum nodosum. She describes and 

 figures its method of penetrating the cortex of the latter plant, and 

 endeavours to explain how it is that it does not occur on Fucus also. 

 [According to British authors it is epiphytic upon both Ascophyllum and 

 Fucus, but chiefly upon the former.] 



Developmental History of the Delesseriaceae.l — "W. Nienburg gives 

 a detailed account of the germination and development of the Delesseri- 

 aceas, paying special attention to the subsequent history of the segments 

 successively cut off from the apical cell in Nitophyllum, Delesseria, etc., 

 and illustrating the same by figures in the text. 



Notes on Lithothamnia.§ — M. Foslie publishes some remarks on 

 Lithotlt amnion murmanicum Elenkin, and the question of its affinity 

 with L. nodulosum and L. vardoense Fosl. He thinks L. murmanicum 

 to be probably identical with L. breviaxe Fosl., and adds critical notes 

 on various species, giving photographs of L. breviaxe and L. vardoense 

 and a figure of L. tophiforme Ung. 



The same author || treats of species in the following genera : Litho- 

 thamnion (9), Lithophyllum (5), Mastophora (2), Fhymatolithon (1), 

 Clathromorphum (1), and Melobesia (1), giving descriptions and critical 

 notes. 



* Ber. Deutsch. Bot. Gesell., xxvia (1908) pp. 476-9 (figs.). 



t Beih. Bot. Centralbl., xxiv. 2te Abt. (1908) pp. 112-16 (figs.). 



% Bot. Zeit., lxvi. (1908) pp. 183-209 (1 pi. and 47 figs.). 



§ K. Norske Vidensk. Selsk. Skrift, 1908, No. 2, 8 pp. (2 pis. and fig.). 



|| Tom. cit., No. 7, 20 pp. 



