42 FROM AN EASY CHAIR 



carefully picking insects from one another^ fur." 1 " The 

 fact is that it is this very habit of " picking " which 

 prevents monkeys from harbouring fleas. Whereas a 

 dog or a cat can only scratch, the monkey has an 

 opposible thumb and delicately sensitive fingers. That 

 which has become the hand of man, with all its marvel- 

 lous skill and efficiency, has been elaborated in its early 

 stages as a means for keeping the hair clean. When 

 monkeys are seen carefully removing something with finger 

 and thumb from their own or their companion's hair, it 

 is not an insect but a little piece of fatty secretion and 

 scurf which is thus removed. The habit, which seems to 

 be general in all kinds of monkeys, even with the 

 anthropoids, such as the chimpanzee and the orang, has 

 of course been efficient in removing any parasitic insects 

 which may at one time have infested monkeys all 

 other furry animals are liberally supplied with them, as 

 also are birds but is now preventive of any re-establish- 

 ment of such visitors. The popular judgment of the 

 monkey's habit is similar to that of the Japanese Aino, 

 who remarked to a traveller who arranged to have a 

 bath in his room every day that he must be a very 

 dirty man to require it. 



1 6. The. Jigger Flea 



One flea is recorded as having been once taken on 

 an anthropoid ape (a gorilla), and is the u jigger, "Pulex 

 penetrans. This is a very serious pest, the history of 

 which shows how man himself opens up the path by 

 which dangerous diseases spread. The jigger-flea was 

 originally known only in the South American tropics. 

 It spread from there to the West Indies in the last 

 century. It burrows into the skin, usually between the 

 toes, but elsewhere also, and causes an abscess and sore 

 as big and deep as a hazel-nut. Several such cavities at 



