ACARINA. 



Fig. 290. Parasites. Acarina. 



i, Louse, Human; magnified 50 diameters. 2, Acarus domesticus, Cheese- 

 Mite ; under surface. 3, Sarcoptes Scabiei, Itch-Insect ; magnified 350 dia- 

 meters. 4, Entozoon folliculorum, Grub from the human skin in various 

 stages of existence, from the egg upwards : magnified 350 diameter? 

 (The small circles near represent the objects about the natural size ) 



