DWELLINGS 1619 



entrances to the central burrows in the mound; there 

 are usually several smaller outside burrows. The 

 entrance to some of the principal burrows is some- 

 timrs four to six feet across the mouth, and some- 

 times it is deep enough for a tall man to stand in up 

 to the waist. 



Certain rodents have carried hollow dwellings to 

 great perfection. Among these the hamster of 

 Germany (Cricteus frumentarius) is not the least 

 ingenious. To his dwelling-room he adds three or 

 four storehouses for amassed provisions. The burrow 

 possesses two openings: one, which the animal pre- 

 fers to use, which sinks vertically into the soil; the 

 other, the passage of exit, with a gentle and very 

 winding slope. The bottom of the central room is 

 carpeted with moss and straw, which make it a warm 

 and pleasant home. A third tunnel starts from this 

 sleeping chamber, soon forking and leading to the 

 wheat barns. Thus during the winter the hamster 

 has no pressing need to go out except on fine days 

 for a little fresh air. He has everything within his 

 reach, and can remain shut up with nothing to fear 

 from the severity of the season. 



It is not only the soil which may serve for retreat; 

 wood serves as an asylum for numerous animals, who 

 bore it, and find in it both food and shelter. In this 

 class must be placed a large number of worms, in- 

 sects, and crustaceans. One of these last, the Chelura 

 terebrans, a little amphipod, constitutes a great 

 danger for the works of man. It attacks piles sunken 

 to support structures, and undermines them to such 

 a degree that they eventually fall. 



