AOABINA — PARASITES. 



335 



vity, the female acarus slips through it, lays het eggs in the folds of the 

 mucous membrane, where they are gradually developed ; issuing forth 

 from the egg, they select some portion of the snail's body upon which 

 to feed and perfect their growth. 



The IxodidcB are furnished with a powerful rostrum, armed with 

 recurved spines, with which they pierce the skin of the unfortunate 



fig. 164. 



1. Parasite of Eagle. 2. Parasite of Vulture. 3. Parasite of Pigeon. 



The circles enclose the objects of about life size. 



animals upon Avhose blood they live. So firmly does this anchor-like 

 organ retain its hold, that if the parasite be pulled away it usually 

 carries a portion of the skin of its victim with it. These creatures 

 live upon a great variety of animals. The dog is very liable to their 

 attacks, and many species attach themselves exclusively to serpents and 



