COLLECTED IN THE SOUTH ORKNEYS. 297 
B. YELLow Syow. (Cf. Plates 10 and 11.) 
Three samples of this peculiar type of snow flora were included in the 
material from the South Orkneys: Nos. 1 and 3 were collected on the same 
date (Feb. 7th, 1904), and agreed almost completely with one another, while 
No. 2, which was collected about a year earlier (March 27th, 1903), was 
relatively poor in algal forms (perhaps owing to its being the end of the 
Antarctic summer), consisting largely of hairs and other foreign particles. 
A part from this, however, such forms as were present were the same as those 
found in the other two samples. АП three samples came from the same 
locality. 
Samples 1 and 3 contained a considerable quantity of algal material and 
show that the vellow snow flora, when well developed, must form extensive 
masses, In reply to enquiries, Dr. R. N. Rudmose Brown has very kindly 
furnished me with the following particulars. I quote from his letters ;— 
“ Both red and yellow snow are rare at the South Orkneys, and many 
apparent cases of the latter which I examined were due only to penguin 
manure. The samples I sent you were taken towards the end of the summer 
on а snow-covered plain called the Beach, that was certainly often frequented 
by penguins, but did not contain a rookery. The samples were gathered on 
the surface of snow that had fallen some little time past—perhaps two or 
three days,—and whose surface had been slightly melted by the sun. І do 
not remember ever seeing any coloured snow in winter, but at that season 
snow was falling so continuously and drifting so incessantly that any growth 
would be immediately covered over. October to February is the warmest 
season, but the mean temperature even then is not above 32°F. .... The 
colour of the yellow snow is fairly bright. I do not remember any brown 
snow, nor have I any record of a green pateh being mixed with a yellow one. 
The Alp: were оп the surface and perhaps two or three or even four milli- 
metres down mixed with the snow, but in sufficient abundance to give an 
unmistakable pale (bright yellow) patch. Yellow and red snow were quite 
distinet from one another; they may in places have been within 30 or 50 
yards of one another, but this was not habitual, and I do not remember 
a single case of the two adjoining one another." 
А considerable number of papers have been published dealing with the 
type of algal flora known as red snow *, which has been recorded from alpine 
(temperate and tropical), arctic, and antarctic localities. Brown and green 
snow have also been described both from alpine and arctie regions f, while 
* See Section С of this paper; also J. Roy,“ The Flora and Fauna of Snow and Ice," 
Scottish Naturalist, viii, 1855-86, pp. 122-127. 
t Wittrock, V. B., * Om snóns och isens flora," in Nordenskiöld, * Studier och Forskningar 
föranledda at mina resori höga norden, 1883, pp. 65-115; see also Wittrock, V. В., “ Die 
у? 
