A BLOOD-THIRSTY PEST. 117 



for a day or two a perfect misery. We owe them a deep 

 gradge ; for on many occasions in South Mexico they have 

 rendered the exploration of hkely-looking bird-haunts 

 a physical impossibihty. We mention them from the 

 interest they inspire from the point of view of how they 

 came to have their origin on such an isolated island, and 

 of how they can possibly manage to exist ; for the chance 

 of getting a meal off an ornithologist, or the extremely 

 few visitors to their island, seems such a rare event to look 

 forward to in their Hves that it can be assuredly ignored. 

 Strangely enough, I saw no ticks on any of the rats, and 

 none on the birds ; and certainly an iguana ought to be 

 proof against their burrowing propensities. 



