ANIMAL PARASITES 173 



hungry creature happens to attach itself to the 

 clothing of a human being, it will make the best 

 of a bad job, and at the same time teach its host 

 a lesson in natural history. 



The pig, also, h is special persecutors of its 

 own, and is often waited upon by the ferocious- 

 looking creature shown in Fig. 112. Members of 

 this family of pes's also patronise the field-mouse, 

 rat, dog, ox, ass, horse, rabbit, squirrel, camel, 

 monkey, &c. They resemble each other very 

 closely, although of different species; and one of the 

 common characteristics of the various genera is 

 the strong development of their legs, all of which, 

 as our illustration shows, are adapted for climbing 

 and holding firmly to their victim. 



Birds, both great and small, surfer equally with 

 mammals in the matter of troublesome visitors. 

 The parasite of the ostrich shown in Fig. 113 is a 

 formidable-looking example, but, taking into con- 

 sideration the size of its host, perhaps it is only in 

 the natural order of things. The parasite of the 

 crow (Fig. 114) is content with more reasonable 

 dimensions ; and the common domestic fowl, along 

 with many other familiar birds, provides board and 

 lodgings for very similar parasites to this of the 

 crow ; while the pigeon, amongst its variety of 

 such uninvited guests, possesses one at least of 

 this family. Perhaps, however, the most interest- 



