THE ELEPHANT SHREW 33 



ment. Both are inhabitants of the Sahara, a happy- 

 hunting ground for predaceous birds and venomous 

 snakes and scorpions. Large eyes and ears are in 

 both cases necessary for a nocturnal animal which 

 in the obscurity of night must ever be on the alert 

 to recognise food or to ward off danger. Length of 

 limb conduces to speed — hence safety by flight — 

 while the tawny coloration confers invisibility by 

 harmonising with the sand and stones of the desert. 

 The trunk of the shrew is, of course, a special 

 development not paralleled by the jerboa. 



It seems possible that this strange outward re- 

 semblance, whether one class it as an instance of 

 true mimicry or not, may benefit one if not both 

 of the parties concerned. Jerboas are relatively 

 abundant (being frequently imported into England 

 as pets) ; the elephant shrew is very scarce and local 

 even in the localities which it inhabits. Hence if 

 the shrews are less fleet than the jerboas they might 

 escape detection amongst their swarming rodent 

 companions, and a half-hearted pursuer mistaking a 

 slow-footed macroscelides for a nimble jerboa might 

 prematurely abandon the chase. This suggestion 

 gains weight from the fact that other instances of 

 insectivores mimicking rodents are known. The 

 Asiatic tupaias or tree shrews simulate squirrels 

 in their rodent-like attitudes and bushy tails; 

 doubtless it is advantageous to them to be 

 mistaken for such active animals as squirrels. 



