26 A NATURALIST IN BORNEO 



insects ; they certainly feed to some extent on fruit. 

 Mr. H. N. Ridley J has seen in Singapore a Tupaia 

 ferruginea capture and drag off into the jungle a large 

 Bull- Frog, Calhila pulchra ; presumably the Shrew cap- 

 tured the frog in order to eat it, and this in spite of 

 the fact that Callula pulchra exudes a sticky substance 

 from the back when irritated. Even if insects were the 

 staple form of the Tree-Shrew's diet, there is no reason 

 to suppose that any insects are endowed with sufficient 

 intelligence to appreciate the differences or resemblances 

 existing between any two groups of mammals ; the mere 

 approach of any mammal, bird or reptile, is enough to 

 scare away a palatable insect from its resting-place, a 

 fruit-eating Squirrel acting quite as efficiently in this 

 respect as a Tupaia. In other words, the disguise of 

 the Tupaia if disguise it be has not been gained for 

 the purpose of deceiving creatures so low in the scale 

 of creation as insects. For my own part, I believe that 

 if we are to regard these resemblances as mimetic, the 

 advantages of the mimetic association are on the side 

 of the Squirrels ; that is to say, it is the Squirrel which 

 mimics the Tupaia, not the Tupaia the Squirrel. A 

 Squirrel is a toothsome morsel, as any one can find 

 out for himself : a Tupaia is just the opposite, as I 

 and one or two other naturalists have found out by 

 actual experiment. If the tastes of the animals which 

 prey on such small deer as Squirrels at all coincide 

 with those of man, I can well imagine that an animal 

 which had once killed and eaten a Tupaia would not 

 desire to repeat the experiment unless hard-pressed by 

 hunger, and if a few Squirrels out of some hundreds 

 escape on account of their resemblance to Tree-Shrews 

 1 Journ. Roy. As. Soc. S. Br., No. 45-(i9o6), p. 279. 



