CHAPTER III. 



APHANIPTERA. 

 (now included in nematocera.) 



The Aphaniptera are also known under the following names : 



Suctoria, De Geer. 

 Siphonaptera, Lat. 

 Aptera, Lam. 



The following may be taken as the characters of the section or 

 sub-order and thus of the family Pulicid^ : 



Parasitic, with scale-like rudimentary wings, the metathoracic scales 

 being the largest. Tarsus five-jointed ; antenna small ; mouth 

 formed for suction, composed of mandibles and lingua, long ; 

 maxillae small, in form of triangular scales with four-jointed palpi ; 

 labium minute, three-jointed ; palpi four-jointed. 



There are four genera: i. Pulex ; 2. Sarcopsylla {i\\t latter not 

 being British) ; 3. Hystrkhopsyl/a, and 4. Typhlopsylla. 



The history and changes of the " fleas " have been known since 

 the days of Aristotle. He noticed their distinct sex, and that they 

 produced o-x-uiXri; wotidn?. He did not trace the changes of this insect 

 far enough, and thus fancied this progeny was sui goieris. He also 

 thought that the adults were generated in the earth spontaneously. 

 This spontaneous generation has been held up by many naturalists 

 since his time, and has been applied to many of the invertebrate 

 animals. I have even, in this nineteenth century, heard people 

 talking of the spontaneous generation of "green fly" and locusts ; 

 but happily this absurd notion is only lingering on amongst very few 

 people. Few animals have had so many theories applied to their 

 origin as the common flea ; Scaliger thought they were produced 

 from humours amongst the hairs of dogs. By degrees their true 

 history became known, and to De Geer we are indebted for one of 

 the first good accounts of their transformations. They have attracted 

 attention in all parts of the world. They were formerly thought to 



