144 Objects for the Microscope. 



CHAPTER V. 



PARASITES. 



A GREAT many objects are sold for those who are curious 

 in learning the forms of those " living creatures " which 

 are nourished on the bodies of higher animals. 



Every animal, from man downwards, is a pasture land 

 for many fellow-creatures. So surely we may call them, 

 formed as they are by the Almighty hand which fashioned 

 our own wonderful body. 



However repugnant it may be to our refined tastes to 

 examine a flea or a louse, this arises from no inherent 

 ugliness of these creatures, but rather from our association 

 with them in scenes of dirt and misery, of personal discom- 

 fort also. Very probably they are the avengers of our evil 

 habits, the consequences of our fallen state, and yet merci- 

 fully ordered to do us good rather than harm, by com- 

 pelling the careless and the poor to that watchfulness and 

 cleanliness which might otherwise be neglected. 



THE FLEA, 



man's great annoyance, is nevertheless a beautifully-formed 

 creature. 



It has to be prepared by long soaking in turpentine, and 

 mounted in balsam, before we can see its various parts. 



The flea belongs to the order of the Suctorida3. The 

 head bears antennae four-jointed ; eyes small, round, and 

 simple ; the proboscis is composed of two long mandibles 

 with serrated edges ; two long narrow plates with fine teeth 

 and longitudinal ribs, these are the lancets ; two leaf-like 

 plates, nearly triangular, which are the maxillae ; two labial 

 palpi, two maxillary palpi, one slender suctorial organ 



