98 BRITISH ARVICOL^, OR VOLES. 



easily watched, and I have frequently observed them 

 on fine balmy evenings in the summer, when the 

 warm breeze gently rustled the waving sedges and 

 water-flags, and bright-coloured dragon-flies hawked 

 on gauze-like wings over the glassy pool in quest of 

 aquatic insects that were emerging from their pupa 

 state towards sunset, when the moor-hen swam out 

 in security from the tuft of reeds which had con- 

 cealed her during the hotter hours of the day, 

 followed by her brood, tiny black balls of down, 

 that chased each other in their play, forming little 

 glistening circlets of silvery light on the water. At 

 these times I have seen the water-voles engaged in 

 foraging for food on the banks, or swimming 

 leisurely about, taking an occasional nibble at some 

 tempting stem, and then diving suddenly and 

 reappearing almost immediately in the same place. 



The water-vole, as far as I have observed, never 

 hybernates during the winter months, but remains 

 perfectly lively, laying up, however, a store of food 

 in its burrow, in anticipation of the inclement season 

 it evidently knows is approaching. 



Besides the common brown kind there is a black 

 variety, found in some parts of England, especially 

 in Hertfordshire and Essex. This has caused con- 

 siderable difference of opinion as to whether it is a 

 mere local variety, or possesses sufficient claims to be 

 considered a distinct species. I have very carefully 



