INSECTA. 305 



the prick of fleas and has dried into black globules, is often found dis- 

 persed by the flea near the eggs that are laid in the chinks of wooden floors, 

 in furniture, &c., and these globules form, according to the observations of 

 DE FRANCE (Ann. des Sc. nat. i. 1824, pp. 440 443) the favourite food of 

 the larvse. These larvae within eleven days are full grown, then spin them- 

 selves up and change into pupae, from which after ten or eleven days the 

 perfect insects appear ; in this way a new generation arises after the lapse 

 of only four weeks. Comp. LEEUWENHOECK, Vierde Vervolg. van Brieven 

 1694. bl. 537 572, 76ste Missive, and KOESEL, Insecten-Belustigung, n. 

 MucTcen und Schnacken, s. 9 24. 



In America, particularly in the Brazils, there is a small species of flea, 

 whose proboscis is longer ; the fore- feet are not so far forward, and whilst 

 the labial palps are wanting, the three threads of the sucker are not sur- 

 rounded by a bivalved sheath. Consequently it has been proposed to 

 make a distinct genus of this species (Sarcopsylla WESTWOOD, Dermato- 

 pnUus GUERIN). This species, which lives in the open air, and is often in 

 great numbers in sandy places, is Pulex penetrans L., DUMERIL, Cons. gen. 

 s. les Insects. PI. 53, figs. 4, 5 ; GUERIN, Iconogr., Insect. PI. 2, fig. 9 ; 

 KOLLAR, Brasilien's vorziiglich Idstige Insecten, fig. 5, s. 8, 9. The Portu- 

 guese call the animal Bicho, the Brazilians Tunga; it bears also the name 

 of Pique, Nigua 1 , &c. and of Chigoe amongst the English residents. Thia 

 insect penetrates beneath the skin of the feet, sometimes also of the hands 

 of man, and of the feet of dogs and other mammals ; the female, after she 

 has penetrated beneath the skin, expands astonishingly, whence malignant 

 ulcers arise, which sometimes occasion death. They infest principally newly- 

 arrived Europeans : see V. HUMBOLDT'S Reise in die ^Equinoctial- Gegenden 

 des neuen Continents, IV. 1823, s. 90, J. J. VON TSCHUDI (who once had six 

 tumours thus caused on his right foot) Peru, Reiseskizzen, I. 1846, s. 310, 

 311. A capuchin monk attempted to transplant a family of these insects 

 from St Domingo to Europe, but his zeal remained unrewarded, for his foot 

 in which he had harboured the colony, was obliged to be amputated on the 

 voyage (KiRBY and SPENCE, Introd. to Entomol. I. p. 102). Comp. on this 

 little animal also DUGES, who especially has illustrated the parts about the 

 mouth, Ann. des Sc. nat. sec. SeVie, Tom. VI. 1836. Zoologie, pp. 129 134. 

 PI. 7 B. A forked caudiform appendage, already figured by CATESBY, and 

 compared by LINNAEUS with the tail of Podura, is probably a male organ of 

 copulation (GUERIN, Iconogr. ) ; at least it does not occur in all individuals. 



OKDER V. Strepsiptera s. Rhipiptera. 



Hexapodal Insects ; (male) with four wings ; anterior wings two 

 small moveable bodies, inserted into the sides of the thorax ; pos- 

 erior wings large, membranous, resembling a quadrant of a circle, 

 olded longitudinally like a fan. (Females apterous, apodous). 



1 Niyua is the name also given to a species of Acarus (Ixodes americanus), which 

 Iso penetrates beneath the skin, and must not be confounded with this flea. 



VOL. T. 20 



