THE LANDING. 251 



goes ? I have finally met with what appears to be such 

 evidence. Twice I have found where moles had made 

 loose tunnels by heaving up the surface of the ground, 

 and coming in contact with a projecting bowlder, had 

 passed beneath it and reappeared at the surface at a 

 point precisely opposite where the descent had been 

 made. In these cases not a particle of earth had been 

 brought to the surface; indeed, could have been so 

 brought. 



More recently I have been fortunate enough to sur- 

 prise chipmunks in short tunnels, and securely closed 

 the openings, and in every case I found that these tun- 

 nels were largely increased in depth, or a curve was 

 made and the animal came to the face of the bluff not 

 far from the opening which I had closed. 



Because a dog, when in pursuit of an animal hidden 

 in some burrow, may scatter the dirt in every direction 

 as he digs, it does not follow that the pursued mammal 

 " made any dirt " at all in excavating his subterranean 

 retreat. Whatever may be true of marmots in other 

 localities, of foxes and prairie-dogs, it is quite evident 

 that where the earth is of so loose a texture as on our 

 sloping terrace fronts, the chipmunk, the mole, the shrew, 

 various snakes and certain insects, find it practicable to 

 construct underground retreats by other means than the 

 complete removal to the surface of the displaced earth ; 

 and further, such is the character of the soil, that actual 

 removal would be fatal to the preservation of the walls 

 of such retreats. Finally, if the earth is not removed, 

 what can become of it, if not compacted by the ani- 

 mal's body as it makes its way forward ? 



