LOUSE. 



the back of the hand, it will thruft its fucker into the fliin, 



and the blood it fucks may be feen pafling in a fine ftrcam 



to the fore-part of the head ; where falling into a roundifh 



cavity, it paffes again in a fine ftream to another circular 

 receptacle in the middle of the head ; from thence it runs 

 through a fmaller veiTel to the bread, and then to a gut 

 which reaches to the hinder part of the body, where in 

 a curve it turns again a little upward. In the breaft and 

 the gut the blood is moved without intcrmiflion with a great 

 force, efpecially in the gut ; and that with fo ftrong a pro- 

 pulfion downward, and fuch a contraAion of the gut, as is 



■very fiirprifing. Power's Mic. Obf. g. 



In the upper part of the crooked afcending gut before 

 mentioned, the propelled blood (lands ftill, and feems to 



• undergo afeparation ; fome of it becoming clear and water- 

 ifh, while other little black particles pafs downward to the 

 anus. 



If a'loufe be placed on its back, two bloody darkifh fpots 



-appear ; the larger in the middle of the body, the leffer to- 

 ward the tail. In the larger fpot, a white film or bl^+dder 



.contrails and dilates upwards and downwards from the head 

 toward the tail, the motions of which are followed by a 



■pulfation of the dark bloody fpot, in or over which the 

 white bladder feems to lie. This motion of the fyftole and 

 diaftole is beft feen when the creature begins to grow 

 weak ; and on pricking the white bladder, which feems to 



'be the heart, the creature always inftantly dies. The 

 lower dark fpot is fuppofed to be the excrements in the 

 guts. 



Lice have been fuppofed to be hermaphrodites, but this 

 is erroneous ; for Mr. Lewenhoeck difcovered that the males 

 have ftings in their tails, which the females have not. And 

 he fuppfrfeslhe fmarting pain the'e creatures fometimes give 

 to be owing to their Hinging witli thefe ftings, when 

 made uneafy by preffnre or otherwife. This accurate ob. 

 ferver fays, that he felt hltle or no pain from their 

 fuckers, though fix of them were feeding on his hand at 

 once. 



The fame accurate obferver determining to know their 

 true hiftory and manner of breeding, put two females into 

 a black Hocking, which he wore night and day. He found, 

 on examination, that in fix days one of them had laid above 

 fifty eggs ; and upon dilTetling it, he found as many yet re- 

 maining in the ovary ; whence he concludes, that in twelve 

 days it would ha%'e laid a hundred eggs. Thefe eggs na- 

 turally hatch in fix days, and would then probably have 

 produced fifty males and as many females ; and thefe females 

 coming to their full growth in eighteen days, might each of 

 them be fuppofed after twelve days more to lay a hundred 

 eggs ; which eggs in fix days more, might produce a young 

 brood of five thoufand ; fo that in eight weeks one louie 

 may fee five thoufand of its own defcendant j. A loufe may 

 be eafily difiecled in a fmall drop of water upon a flip of 

 glafs ; and thus placed before the microfcope, it is common 

 to find five or fix eggs of a fize ready to be laid, and fixty 

 .or feventy others of different bignels. In the male the 

 penis is very remarkably diftinft, as are alfo the teltes, of 

 which he feems to have a double pair, as is alfo the fting, 

 the ftrucf ure of which merits a peculiar attention. Lewen- 

 hoeck's Arcan. Natur. torn. ii. p. 78. 



Many animals, both of the quadruped and flying kinds, 

 jire fubjefl to lice : but thefe are of peculiar fpecies on each 

 animal, and are not at all like thofe which infelt (he human 

 body. Nay, even infefts are infefted with vermin, which 

 feed on them and torment them. Several kinds of beetles 

 arc very fubjeft to iice j buj particularly that kind called 



thence the loufy Icelk. The lice on this are very numerous, 

 but will not be fiiook off. The ear-wig is often infefted 

 with lice juft at the fetting on of its head ; thefe are white 

 and fhining like mites, but they are much fmaller ; they are 

 round-backed, flat-bellied, and have long legs, particularly 

 the foremoll pair. Snails of all kinds, but efpecially the 

 large naked kinds, are very fubjecl to lice, which are con- 

 tinually feen running about them, and devouring tliem. 

 Numbers of little red lice, with a very fmall head, and in 

 (hape refembling a tortoife, are often feen about the legs of 

 fpiders, and they never leave the fpider while he lives, but 

 if he be killed, they almoft inftantly forfake him. A fort 

 of whitifh hce are very common on humble-bees ; they are 

 alfo found on ants ; and many forts of fifties are not lefs 

 fubjcft to them than the land animals. Kircher fays, that 

 he has found lice alfp on flies. Baker's Microfcope, 

 p. 182. 



Signior Redi, who has more accurately examined thefe 

 creatures than any other author, has engraved feveral fpe- 

 cies found on different animals. He calls thofe found on 

 beafts lice, and thofe found on birds fleas. He is of opi- 

 nion, that every fpecies of birds has its peculiar fort of flea, 

 different from thofe of other birds ; and has obferved that 

 they are hatched white, but that they gradually acquire a 

 colour, like that of the feathers they live among,' yet they 

 ufually remain tranfparent enough for a good microfcope to 

 difcover the motion of their inteftines. The kinds lie has 

 obferved are thefe : on the hawk three different forts ; on 

 the large pigeon, the turtle-dove, the hen, the ftarling, the 

 crane, the magpie, the heron, the lefTer heron, the fwan, 

 the turkey, the duck, the fea-mew, the fmall fwan, the 

 teal, the caftrel, the peacock, the capon, and the crow, on 

 each one fort ; on the moor-hen three forts ; on the wild 

 goofe two forts ; and on the crane, befide the common one, 

 a white fort, marked, as it were, with Arabic charaiSers. 

 Men, he obferves, are fubjeCl to two kinds, the common 

 loufe, and that called the cra^ loufe. He alio found pecu- 

 liar forts on the goat, the camel, the afs, the African ram, 

 the ftag, which has, like many of the birds, two kinds, and 

 on the hon and the tyger. The fame author has obferved, 

 that the fize of thefe creatures is not at all proportioned 

 to that of the animal they are to inhabit, for the ftar- 

 ling has them- as large as the fwan. Redi, Gen. Iiil. 

 p. 312. 



It is obfervable, that fome fort of conftitutions are more 

 apt to breed lice tlian others ; and that in certain places of 

 different degrees of heat, they are very certain to be do- 

 ilroyed upon people, who in other clifnates are overrun witli 

 them. It is an obfervation of Oviedo, that the Spanifh 

 failors, who are generally much afflifted with lice, always 

 lofe them in a certain degree in their voyage to the Indies, 

 and luive them again on their coming to the fame degree at 

 their return : this is not only true of the Spaniards, but of 

 all other people who make the fame voyage; for though 

 they fet out ever fo loufy, they have not one of thefe crea- 

 tures to be found after they come to the tropic. And in 

 the Indies there is no fuch thing as a loufe about the body, 

 though the people be ever fo uafly. The failors continue 

 free from thefe creatures till their return; but in going back 

 they ufually begin to be loufy, after they come to about the 

 latitude of Madeira. The extreme fweats which the work- 

 ing people naturally fall into between tliis^Jatitude and the 

 Indies, drown and deftroy the lice, and are of the fame ef- 

 feft as the rubbing over the loufy heads of children with 

 butter and oil. The fweat in and about the Indies is not 

 rank as in Europe, and therefore it is not apt to breed lice; 

 but when the people return into latitudes where they fweat 



rank 



