THE NEOTOMAS, OR PACK RATS 33 



rolling, it is the more unapparent how she 

 keeps herself from being pierced through and 

 through with dozens of needles, especially about 

 the mouth, breast, and feet. I have seen the 

 cholla joints piled up in stacks or lodged 

 about the entrance of the burrow in such num- 

 bers that their total bulk would have filled 

 several barrels. In another instance I noticed 

 cactus joints piled two and three deep over an 

 area of at least forty square feet in front of the 

 burrow. The nest was situated high up on a 

 bank and back under a ledge of rock in such a 

 position that every one of those horrible as- 

 semblages of cactus needles had to be carried 

 at least forty feet over steep and uneven rock 

 surfaces, the nearest shrub of cholla being that 

 distance from the nest. 



This nest was entered by either of two open- 

 ings. In order that I may explain the ingenious 

 method that the neotoma used to protect these 

 runways from being entered by an enemy, I 

 have drawn the accompanying map of the 

 space in front of the dwelling. An examination 

 of the figure will show that every approach to 

 the holes is most carefully protected by the 



