BUGS. 



211 



FIG. 291. Perlicu- 

 lus vestimenti, 

 body-louse. 



about a week from the time that they are laid. At first the larvae seem very trans- 

 lucent and delicate, but their skin speedily hardens and they move actively about to 



select a spot upon which to settle and suck the warm blood of 



their tender victim. 



The second species, or body-louse, is somewhat larger and 



more slender than the preceding, the color is generally tinged 



with gray, the legs are longer and thinner, the head is more 



contracted behind, and the second joint of the antennae is 



elongated. It is commonly about a line or somewhat more in 



length. It may be of some interest to notice that this is the 



form common to military camps in all temperate climates, as 



well as to careless persons who dwell in uncleanly apartments 



and who neglect to change their clothes. During the late civil 

 war in the United States it was widely distrib- 

 uted by means of the railroad cars and other con- 

 veyances which transported troops. It affects 

 the skin of most parts of the body, but espec- 

 ially selects the chest and back. 



The female attaches her eggs to fibres in the 



O 



seams of undergarments, from which the larvae 

 hatch in about one week. Leewenhoek has esti- 

 mated that an ordinary female would produce 

 about five thousand young ones within a period 

 of eight weeks. In some countries of Europe, 

 as Russia and Poland, this species is widely disseminated, and 

 is by no means confined to the poor and degraded. It takes 

 about one month for an individual to reach maturity ; but the 

 duration of life seems not to have been determined for any of 

 the forms. 



In the subgenus Hcematopinus, which can hardly be sepa- 

 rated from the typical Pediculus, various authors have placed 



the louse of the swine, also that of the 

 horse, ass, buffalo, squirrel, etc. A form 



is found upon some of the large Asiatic monkeys that measures 

 nearly one-fourth of an inch in length. Thus far about twenty- 

 five nominal species have been referred to this family ; but no 

 doubt a host of others will yet be discovered when the various 

 animals shall have been examined for this purpose. 



We now reach a group of the Parasita, which has lately 

 been brought to notice by the publications of Professor West- 

 wood of Oxford, the POLYCTENID^E. Certain bats of the genus 

 Molossus, one inhabiting China, the other the West Indies, were 

 found to harbor very peculiar lice of a type previously unrecog- 

 nized. These have been described and figured in his beautiful 

 Thesaurus Entomologicus Oxoniensis, from which we derive the 

 following particulars : They have a long elliptical, or somewhat 

 quadrate outline, with legs joined by rounded, free coxae to the underside of clearly 

 defined and well separated pectoral segments, the first pair short, stout, with three- 



FIG. 290. Rostrum of 

 body-louse. 



FIG. 292. Hmnatopinus 

 vitu/i, louse of cow. 



