DISCOLORATION OF THE ARCTIC SEAS. 319 



than the green. Thus, as Brown, in the article above referred to, 

 remarks, the presence of this slime, inconsiderable as it is, but 

 spread over hundreds of thousands of square miles, is a condition 

 necessary for the subsistence, not only of the swarms of Birds that 

 frequent the northern seas, but also of that giant of the animal 

 creation, the Whale, and all branches of industry dependent on 

 Whale-fisheries. 



Of these remarkable organisms Dr. Oberg collected specimens 

 when possible, during the voyage, which it is intended hereafter 

 to submit to a careful scientific examination, in conjunction with 

 similar specimens from preceding expeditions. Here we need 

 only mention that the slime itself in each particular place is 

 formed only of a few species of Diatomaceae*, often so large that 

 after drying the mass the siliceous frustules may be discerned 

 with the naked eye ; but, on the other hand, different parts of the 

 ocean exhibit entirely difierent forms, so that, for example, the 

 green slime in one place has sometimes not a single species identical 

 with that in another. A long continued collection will therefore 

 be required to explain this scanty, but nevertheless remarkable, 

 and we may safely say important, Flora of the ocean's surface. 



XXXYII. — Notes of Diatomace^ from Danish Green- 

 land, collected by Robert Brown. By Professor 

 Dickie, Aberdeen. 



[Reprinted, by Permission, from the Trans. Bot. Soc. Edinburgh, 

 vol. x., pp. 65-67. Read January 14, 1869.] 



Mr. Brown sent for examination small packets of material 

 collected at various places along the coast of Danish Greenland, 

 with a request that any Diatomaceae they contained might be 

 recorded. 



The larger marine Algae, from high northern latitudes, I have 

 invariably found to yield abundance of these organisms. The 

 species collected by Mr. Brown, as well as his special Diatomaceous 

 gatherings, have not yet been seen by me, and therefore the 

 present communication gives but an imperfect idea of the marine 

 Diatomaceae in the localities visited. 



No. 1. A small mass, chiefly of Hypnum fluitans^ in the sea at 

 Jakobshavn, contained the following : — 

 Cocconeis scutellum. Rhabdonema arcuatum . 



Coscinodiscus eccentricus. Cocconema cistula. 



Stauroneis pulchella. C. parvum. 



Hyalodiscus subtilis. 



The two latter are freshwater species, and were, doubtless, 

 attached to the Hypnum before it was conveyed to the sea ; the 

 marine species seem not merely entangled among the mass, but 

 attached to it. 



