164 



THE MINDS AND MANNERS 



The habitants had chosen to locate their fortress between 

 a large creosote bush and a tree-choya cactus (Opuntia fulgida) 

 that grew on bare ground, twelve feet apart. When away from 

 home and in danger, the pack rats evidently fled for safety to 

 one or the other of those outposts. Between them the four 

 entrance holes, then in use, went down into the earth; and there 

 were also four abandoned holes. 



Connecting the two outposts, — the creosote bush and the 

 choya, — with the holes that were in daily use there were some 



Small Creosote 



Length shown, 15 feet. , 

 Large Creosote Bush 





Abandoned holes w Q 



Holes in usErC 



VtXH. 



FORTRESS OF A PACK-RAT, AT TUCSON DEFENDED BY THE SPINY 

 POINTS OF THE TREE CHOYA (OpUfltia fulgida) 



much-used runways, as shown on the map; and each side of 

 each runway was barricaded throughout its length with spiny 

 joints of the choya. A few of the joints were old and dry, but 

 the majority were fresh and in full vigor. We estimated that 

 about three hundred cactus joints were in use guarding those 

 runways; and no coyote or fox of my acquaintance, nor eke a 

 dog of any sense, would rashly jump upon that spiny pavement 

 to capture a rat. 



Beyond the cactus outpost the main run led straight to the 

 sheltering base of a thick mesquite bush and a palo verde that 

 grew tightly together. This gave an additional ten feet of 

 sa fe ground, or about twenty-five feet in all. 



On our journey to the Pinacate Mountains, northwestern 



