120 TEOPICAL NATURE, AND OTHER ESSAYS. 



obliged to sleep completely muffled up, in order to avoid 

 being made seriously ill or even losing their lives. The 

 exact manner in which the attack is made is not posi- 

 tively known, as the sufferer never feels the wound. The 

 present writer was once bitten on the toe, which was 

 found bleeding in the morning from a small round hole 

 from which the flow of blood was not easily stopped. 

 On another occasion, when his feet were carefully covered 

 up, he was bitten on the tip of the nose, only awaking 

 to find his face streaming with blood. The motion of 

 the wings fans the sleeper into a deeper slumber, and 

 renders him insensible to the gentle abrasion of the 

 skin either by teeth or tongue. This ultimately forms a 

 minute hole, the blood flowing from which is sucked or 

 lapped up by the hovering vampyre. The largest South 

 American bats, having wings from two to two-and-half 

 feet in expanse, are fruit-eaters like the Pteropi of the 

 East, the true blood-suckers being small or of medium size 

 and varying in colour in different localities. They belong 

 to the genus Fhyllostoma, and have a tongue with horny 

 papillae at the end ; and it is probably by means of this 

 that they abrade the skin and j^roduce a small round 

 wound. This is the account given by Buff on and Azara, 

 and there seems now little doubt that it is correct. 



Beyond these two great types — the monkeys and the 

 bats — we look in vain among the varied forms of mam- 

 malian life for any that can be said to be distinctive of 

 the tropics as compared with the temperate regions. 

 ]\Iany peculiar groups are tropical, but they are in almost 

 every case confined to limited portions of the tropical 

 zones, or are rare in species or individuals. Such are 

 the lemurs in Africa, Madagascar, and Southern Asia ; the 



