LIFE ON SNOW. 67 



very rock, a depth of twelve feet. The same phenomenon 

 has been observed in other parts of the Polar reojions, on 

 the glaciers of the Alps, and in other similar circum- 

 stances. Scientific investigation has proved this colour 

 to be caused by the excessive abundance of minute organ- 

 isms, mostly vegetable, of a very simple character, in the 

 form, according to Dr Greville, of a gelatinous layer, on 

 which rest a vast number of minute globules, resembling, 

 in brilliance and colour, fine garnets.* Professor Agassiz, 

 however, maintains that these globules are not vegetables, 

 but the eggs of a minute though highly-organised animal, 

 one of the Rotifera, named Philodina 7vseola, which 

 animal he found in abundance, with the globules, in the 

 glacier of the Aar.-|- Other minute animals were also 

 found in the snow. 



In Canada I have found, in the depth of winter, living 

 and active insects on the surface of the snow, which are 

 seen nowhere else, and at no other season. Little hop- 

 ping atoms, of singular structure, adapted to a mode of 

 progression peculiarly their own, dance about on the un- 

 sullied bosom of the new-fallen snow. They belong to 

 the genus Podura, and are distinguished by having at 

 the extremity of their body two long, stiff bristles, ordi- 

 narily bent up under the belly, but which, at the pleasure 

 of the insect, fly out straight with great force, and thus 

 jerk it into the air, on the principle of a child's toy-frog. 

 Other curious species, — two in particular, both belonging 

 to winged families, yet both without wings, the one a sort 



* See Cryptog. Flora, p. 231. f Rep. Br. Assoc, 1840. 



