NO. 16.] PROTOZOA ON THE ICE-FLOES OF THE NORTH POLAR SEA. 



state that "in the water a great deal of smaller mucous lumps were also 

 floating; they were partly white partly yellowish red, and I collected many 

 of them. Under the microscope they appeared to be composed of accumula- 

 tions of diatoms and a great many round red cells (see PI. VIII, Figs. 7 & 8) 

 filled with round refractive red globules". This large, globular alga (PI. VIII, 

 Fig. 7 & 8) gave the lumps their reddish colour, where, however, this alga 

 had died and become colourless, the lumps got a white appearance externally. 

 "These lumps of diatoms and alga? were all of them floating at a certain 

 depth, about 1 metre l under the water-surface, where in some small channels 

 they might occur in great quantity. At the same depth the above mentioned 

 greenish brown alga (Melosira) was also chiefly distributed, whilst parts of it 

 rose to the surface. These parts were often greenish brown as usual, but also 

 often whitish and were evidently dead. It is clear that the lumps of diatoms 

 as well as the Melosira keep themselves floating just at the depth where the 

 upper layer of fresh-water (melting-water from the ice) rests on the under- 

 lying salt sea- water. The water on the surface was perfectly fresh 2 (i. e. it 

 could be used as drinking water) and the lumps of diatoms sank in it, whilst 

 they floated when they came lower down". (Fig. A, d). 



These floating lumps composed of diatoms and the unknown red glo- 

 bular alga (PI. VIII, Figs. 7 & 8) were very fragile and fell to pieces as soon 

 as they were touched. They therefore had to be collected with great care. 

 In these lumps I also found numerous Infusoria, and other small protozoa 

 moving about between the diatoms; they were very similar to those found 

 in the accumulations of diatoms in the ponds on the ice-floes. 



The diatoms found in these free-floating lumps, as well as on the "ice- 

 foot" and in the ponds on the ice have been described by Professor H. H. Gran 

 in a special memoir (No. 11, in vol. IV of this Report). 



I studied on the spot, as well as I could, the Infusoria and other Protozoa 

 found along with these diatoms, and at the same time I made numerous 

 drawings of them, some of which have been reproduced on Pis. I— VIII. 



Not being conversant with the subject and having no literature of the 

 kind at hand, I could not determine the species, but could only make 



1 Somewhat later in the season, the thickness of the layer approached 2 metres, at least 



in some channels. 

 1 It contained between 1 and 2 per mille salt. 



