56 Mr Shuttle worth on the Colouring Matter 



I shall with them begin my description of the organized sub- 

 stances which formed the red snow. 



1*/, The bodies by much the most striking, and which, 

 from their great number, and deep colour, mainly produced 

 the red tint of the snow, were small infusoria of an oval form, 

 whose colour was a very deep reddish-brown, and which were 

 nearly opaque. Measured by the micrometer, their greatest dia- 

 meter was about -^^ of a millimetre, and their smallest about xiiy. 

 (Fig. 3. pi. 1.) They traversed the field of vision with asto- 

 nishing rapidity, and in all directions. Although the majority 

 were perfectly oval, with rounded extremities, there were some 

 pear-shaped — that is to say, having one of their ends rounded 

 and obtuse, whilst the other gradually became more slender 

 towards a point, where it was apparently obliquely truncated. 

 The motion of the former was horizontally progressive, whilst 

 the others often stopped in the middle of their course, and for 

 an instant revolved rapidly on their pointed extremity without 

 changing their places. In some of the infusoria of the oval 

 form, T observed, near one of the extremities, or the centre, 

 two small oval spots, which were reddish and almost transpa- 

 rent, and which, after the example of M. Ehrenberg, I regarded 

 as stomachs. Besides this, I could discover no other sign of 

 organization ; and on returning home, where I had an oppor- 

 tunity of consulting the great work on the Infusoria, I have 

 not hesitated to regard them as a yet undescribed species of 

 Ehrenberg' s genus Astasia, for which I propose the specific 

 name of Astasia nivalis. (See Ehrenb. Infus. p. 101, tab. 7, 



f. 1.) 



2^, There were among these infusoria, though in very limited 

 numbers, some bodies which were much larger than those above 

 described, in shape round or oval, of a beautiful blood-red co- 

 lour, inclining to crimson, and which were, to a considerable 

 extent, transparent, and surrounded with a margiii or colourless 

 membrane. Their dimensions varied from ^^ to jq of a milli- 

 metre. (Fig. 4. pi. 1.) Although I have not been able to observe 

 any movement, nor the slightest trace of internal organiza- 

 tion, I have no doubt that these are infusory animals, and I re- 

 gard them as constituting a new species of the family of Volvo- 

 cians, and of the genus Gi/ges of MM. Bory and Ehrenberg (Cf. 



