HOW ANIMALS LEARNT TO CLIMB 103 



rodents, including even the guinea-pig, are good 

 swimmers. The number which can climb is far more 

 limited, and the line seems drawn not by lack of 

 physical equipment, but by lack of experience, or 

 possibly of the desire to do so. There is, for instance, 

 a regular series, from the tree squirrels through the 

 ground squirrels to the prairie-dogs and marmots, 

 of very closely allied rodents. The squirrels are at 

 the head of the second rank of climbers, though the 

 lack of "swinging power" in their arms puts them 

 below the monkeys. The ground squirrels can 

 climb trees well enough, though they are terrestrial. 

 But the prairie-dogs and marmots, though the former 

 are almost as well equipped for climbing as a rat, have 

 never properly learnt the art, and though not afraid 

 to try, the former come to most lamentable grief in 

 their experiments. Probably the prairie-dogs, which 

 live mainly on level and treeless plains, never have 

 occasion in their lives either to jump or to climb. 

 When loose in a house they try to do both. Being 

 well equipped with claws, and very active, they manage 

 the climbing well enough. But as they have never 

 learnt either to jump or to judge distance, or that 

 smooth upright surfaces offer no hold on alighting, 

 they generally miss their object, and fall violently to 

 the ground. This would not matter, were it not that, 

 as they have large and heavy heads, they usually fall on 

 these, and either stun themselves or break their teeth. 

 This instance of climbing in the experimental stage 

 would be more interesting did we know how the 

 Australian rabbits first learnt to climb, and whether 



