FRESH \\ VIT.I: \\-..r. OH mi Nfl 1 11 .>KKSi:Y8. 119 



this region does nut attain to nearly HO al>iin<l;iiit a development as yellow snow. 1 The 

 number of species present is also smaller. n tin- whole sample 4 was richer in 

 individuals than cither 5 or 6, and showed a somewhat ditfen-ni constitution. Nearly 

 all the forms present were in tin- ivMmi: condition, so that some doubt attaches to 

 certain determinations. Th<- samples <.f n .1 .-now inc-lu-lr.l a <;ood deal of non-algal 

 matti-r, such as hairs, starch grains, pollen grains of /W<-rpiM, etc. 



In coni|>arison with the Horn of the y-llu\v snow we have to note certain similarities 

 ami certain differences. Among the former we may reckon the occurrence of character- 

 istic forms of the ydlow snow flora, such as S<-"tif//<t >tnt>n-<-t-<t, K. K. Fritsch, and 

 Raphidonema nivale, Lagerh. The former was found only in .-.miplcs 5 and G, 

 especially in the latter; the number of individuals was small, but those present were 



..eptionally large size (length of cell about 55^). They appea red to contain the 

 same yellowish fat an in the yellow snow forms; no resting-stages were observed. 

 The /{< i/>l<i < lonema was quite common (especially in sample 4), and in this out 

 agreed absolutely with Lagerheim's description. Apart from fragments of an 

 (Edogonium it was the only filamentous form present 



There are two marked differences from the yellow snow flora. These are (n) the 

 immense preponderance of red spherical cells, no doubt constituting the resting-cells 

 of different members of Chlamydomonadaceaj (see below), ami (l>) the occurrence of 

 various diatoms in all three samples. The resting-cells are of two chief types, viz. 

 with and without a broad mucilage-sheath. The latter type are circular, with a 

 smooth, somewhat thickened membrane and granular contents, with a central pyrenoid 

 (text fig. 1, A, p. 122); the diameter of these cells varies between 10 and 20 M. The 

 red colouring matter in the contents had Wen for the greater part taken up into the 

 preserving fluid, and the cell-contents appeared colourless or slightly greenish ; it is 

 therefore impossible to say what the exact colour of these cells was in nature. A 

 considerable quantity of fat was often present in these resting-cells. They recall very 

 markedly the resting-cells (aplanospores) of Chlamydomonas nii-alis (Sommerf.), Wille 

 ( = Sph#rella nivalis, Sommerf.), as figured by Witt rock. 1 As very few other stages of 

 this alga were found, the determination must, however, remain somewhat doubtful. 

 In one or two cases subdivision of the contents into a number of parts was observed, 

 but this, of course, scarcely aids in determining the species. 



The second type of resting-cell (observed only in sample 4) closely resembles the 

 other type except that the cells are surrounded by a broad sheath of mucilage often about 

 two to three times the width of the cell in diameter (<-f. text fig. 1, C, p. 122') ; in many 

 cases the mucilage was of a deep red colour, probably owing to the colouring matter of 

 the cell having diffused out and stained the mucilage under the influence of the preaenr- 



i '/. lo the remark* on the distribution of red and yellow mow cited on p. 99, from Dr R. N. Rud 

 Brown'* letter*. 



* Wiurock, lot. cii., tab. iii., fig. 1. 



1 The mucilage-sheath wa* often eontidwabljT broader than U ihown in this figure. 



