On the Small Temporary Glaciers of the Vosges. 227 



play, the belly turns upwards. The use of the same parts for motion 

 is seen in the following observation upon them when put into action. 

 The pectoral, and, more particularly, the ventral fins, serve to raise 

 and depress the fish : when the fish desires to have a retrograde 

 motion, a stroke forward with the pectoral fin effectually produces 

 it : if the fish desires to turn either way, a single blow with the tail 

 sends it round at once : if the tail strike both ways, the motion pro- 

 duced by the double lash is progressive, and enables the fish to dart 

 forward with an astonishing velocity. The result is not only in some 

 cases the most rapid, but in all cases the most gentle, pliant, easy, 

 animal motion, with which we are acquainted. However, when the 

 tail is cut off, the fish loses all motion, and it gives itself up to where 

 the water impels it. The rest of the fins, therefore, so far as respects 

 motion, seems to be merely subsidiary to this. In their mechanical 

 use, the anal fin may be reckoned the keel ; the ventral fins, out- 

 riggers ; the pectoral fins, the oars ; and if there be any similitude 

 between these parts of a boat and a fish, observe that it is not the 

 resemblance of imitation, but the likeness which arises from applying 

 similar mechanical means to the same purpose." — (xli. p. 257.)* 

 Owen's Lectures on Comparative Anatomy, vol. ii., p. 145. 



On the Small Temporary Glaciers of the Vosges. By EDWARD 



COLLOMB. 



The winter of 1844-45, which has been remarkable for the 

 large masses of snow which the west wind heaped up on the 

 slopes of some of our mountains (the Vosges), — masses some- 

 times from 15 to 20 metres in thickness, — gave rise to small 

 temporary glaciers, possessing some of the properties of 

 large glaciers, and, among others, a locomotive movement. 

 The duration of these glaciers was limited to a few months ; 

 by the end of July and beginning of August, they had com- 

 pletely disappeared. During this interval, we have had an 

 opportunity of making many observations in reference to the 

 transformation these masses underwent between the winter 

 and summer. 



The first fact that struck us, is the tendency of the snow, 

 when in a large mass, to form itself into stratified layers dur- 

 ing the time of melting. The second fact, is the proper move- 



* See also Carlisle Phil. Trans. 1806, p. 3. 



