Many are the portrayals which are evidently 

 based on Nelson's own personal field knowl- 

 edge, some of them involving facts here for 

 the first time -made known to science. His ac- 

 count of the behavior of kangaroo rats in 

 Lower California is particularly apt in illus- 

 tration of the above statement. 



During several nights I passed hours watching 

 at close range the habits of these curious animals. 

 As I sat quietly on a mess box in their midst . . . 

 [they] would forage all about with swift gliding 

 movements, repeatedly running across my bare 

 feet. Any sudden movement startled them and all 

 would dart away for a moment, but quickly re- 

 turn. . . . They were so intent on the food [grains 

 of rice put out for them] that at times I had no 

 difficulty in reaching slowly down and closing my 

 hand over their backs. I did this dozens of times, 

 and after a slight struggle they always became 

 quiet until again placed on the ground, when they 

 at once renewed their search for food as though 

 no interruption had occurred. . . . While occupied 

 in this rivalry for food they became surprisingly 

 pugnacious. If one -was working at the rice pile 

 and another rat or a pocket mouse approached, it 

 immediately darted at the intruder and drove it 

 away. The mode of attack was to rush at an in- 

 truder and, leaping upon its back, give a vigorous 

 downward kick with its strong hind ' feet. . . . 

 Sometimes an intruder, bolder than the others, 

 would run only two or three yards and then sud- 

 denly turn and face the pursuer, sitting up on its 

 hind feet like a little kangaroo. The pursuer at 

 once assumed the same nearly upright position, 

 with its fore feet close to its breast. Both would 

 then begin to hop about watching for an opening. 

 Suddenly one would leap at the other, striking with 

 its hind feet, . . . [producing] a distinct little 

 thump and the victim rolled over on the ground. 

 After receiving two or three kicks the weaker of 

 the combatants would run away. The thump made 

 by the kick when they were fighting solved the 

 mystery which had covered this sound heard re- 

 peatedly during my nights at this camp. 



The brilliantly coated paper used tlxroughout 

 this book although hard on sensitive eyes, is 



