PULEX PENETEANS. 91 



in both places, and looked after the fleas just at the corresponding 

 spots. The female had an abundance of blood and blood-corpus- 

 cles in her; the male had a reddish fluid, as to the presence of 

 blood-corpuscles in which I was not quite certain. At any rate, 

 the males can extract a bloody serum from the body. 



Some species of fleas of our mammalia also occur temporarily 

 upon man ; for example, that of the dog, &c. These I pass over, 

 howe\ 7 er, although they constitute distinct species. 



2. The Sand-Flea =. Pulex penetrans. 



Synon. : Dermatophilus , Sarcopsylla penetrans, Chique, Cbigue, 

 Pigue, Funga, Punque, Chigger, Gigger, Tschike r TungUa, Attun, 

 Ton, Nigua, Tunga, Xique, Bicko. 



It is smaller than the common flea, and has a proboscis as long 

 as the body, whilst in the common flea this is at the utmost one sixth 

 or one fourth of this length. The valves at the extremity of the 

 male, which only lives in the sand, and does not attack man, are 

 much elongated ; the impregnated female swells up extraordinarily, 

 after it has burrowed under the skin of men and animals. The head, 

 thorax, and feet are only recognised as attached points. According 

 to the statements of most authors, the animal only lives as far 

 as 29 of south latitude in the hot countries of South America, 

 especially in Brazil ; whilst Goudot found it even in the cold 

 region of New Granada, as far as Bogota. According to the 

 journals of Count Gortz, besides sand, this flea likes to dwell 

 in the crevices and joints of pig-styes. Some people suppose that 

 there are two species. Neither the male nor the unfecundated 

 female has yet been seen in the skin of man or the domestic ani- 

 mals. According to A. von Humboldt, it only attacks Euro- 

 peans and not the aborigines ; Martius says that it is attracted by 

 the sweat of the negroes. 



Martiny gives the following notes upon it from Dobritzhofer. 

 This animal is so small that it can only be seen by sharp eyes, 

 with a good light, for which reason the seeking for the flea after 

 its immigration is generally left to children. It perforates the 

 skin down to the flesh, and, concealed in its little canal, swells up 

 into a white, globular vesicle, which in a few days may become 

 as large as a pea, the pain constantly increasing; this is the ab- 

 domen of the female filled with eggs, or, more correctly, with 

 larvse. Neglect of the disorder, or careless rupture of the vesicle, 



