86 



THE AMEEICAN ENTOMOLOGIST. 



juices of the body and causing an intolerable 

 itching-, until they reach maturity, when they 

 come forth out of their burrows to copulate and 

 lay eggs for the future propagation of their 

 species. 



The favorite home of the Head-louse, as be- 

 fore stated, is the head ; that of the Body-louse 

 the more naked parts of the body; the Crab- 

 louse, on the other hand, peculiarl}' affects the 

 human pubes, though it occasionally strays off 

 into the whiskers and the eyebrows.* 



All the above three insects, as well as their 

 eggs, may be readily killed by the application to 

 the infested portions of the body of a small 

 quantity of any kind of mercurial ointment — 

 whether white, red or black is immaterial, 

 though the white is preferable on account of its 

 not soiling the linen. In the case of the Body- 

 louse, however, as already stated, a frequent 

 change of linen is all that is required to rid one's 

 self of the enemy ; and, moreover, the applica- 

 tion of any mercurial ointment to the whole 

 surface of the body, inhabited by this insect, 

 would be injurious to delicate constitutions. 



The Homan Bot-Fly {(Estrusliominis, Gme- 

 lin). — ^Most persons are aware that there is a 

 two-winged fly (CEstrus bovis, Tuinn.), theJarvas 

 of which, both in Europe and America, hatch 

 out from eggs deposited by tlie mother-fly in the 

 hide of the living ox, and cause therein ulcers 

 which are popvtlarly known as "Wormals" 

 (worm holes). There is another species of the 

 same family (Cuterebra cuniculi, Clark), the 

 larvre of which inhabit similar ulcers in the 

 neck of American rabbits; and still another 

 ( Ciderebra emasculator, Fitch) , which in the lar- 



*The scicntilic classiflcaliou of the Liue— inchidiug the Bird- 

 lice (iVirmiis family) ivliich are structurally quite distinct 

 from the True lice {Pedimliis family) that inhabit Mammals- 

 has greatly perplexed naturalists . Some have placed them 

 along with certain allied forms in an order by themselves 

 {A'ptera) as a portion of the great class of Insects; others have 

 considered them as not ti'ue Insects; and Bm-meister has ar- 

 ranged the True lice as a subordinate family of the True bugs 

 order (Hcteroptcra), and the Bird-lice as a subordinate fam- 

 ily of the order Neuroptera. It is generally asserted that the 

 True lice have a beak, M'hile the Bird-lice notoriously have 

 jaws — thus throwing the former among the sucking insects 

 (Haustellata) , and the latter among the biting insects (Mandi- 

 bulattt). The mouth of the True lice is certainly very oli- 

 scurely organized, the head terminating in an elongated, 

 blunt, porrect snout, from which there is occasionally pro- 

 truded a small, indistinctly formed process which is the true 

 mouth. We believe this process can not be a beak, analo- 

 gous to that of the bugs , as Burmeister supposed , because the 

 Crab-louse, as has been already stated, burrows under the 

 human scarf-skin, for which operation jaws of some kind or 

 other are absolutely necessary. We should prefer, therefore, 

 to classify both the Bird-lice and the True lice, as well as 

 the Podura and Lepisma families, among the Pseudo-neurop- 

 tera, as distinct families of that sub-order. For we can see 

 no reason why, if the lice, &c. are to be placed in an order 

 by themselves, on account of their having no metamorphosis 

 whatever, and not even the slightest vestiges of wings, the 

 orthopterous genera, Diapheromera and Phalangopsis and 

 Rhaphidophora, which are as utterly destitute of wings as the 

 lice, and which are as devoid of any larval and jnipal meta- 

 morphosis as the lice, should not also be placed in a separate 

 order. Whether the Pseudo-neuroptcra should be annexed to 

 the Orthoptera or to the true Neitroptera is another and a very 

 distinct question . 



va state mutilates the generative organs of 

 American squirrels, so as to cause that very 

 general emasculation of these animals, which 

 has been erroneously attributed, by many, to 

 battles between the old and the j'oung males. 



In several parts of South America a larva be- 

 longing to this same family of insects, inhabits 

 " wormals" in the human body, the parent fly 

 having every facility for depositing its eggs in 

 the naked bodies of the natives, and being 

 enabled to attack civilized foreigners whenever 

 they strip to bathe. Since, however, this fly is 

 not found in North America it will not be ne- 

 cessary to say anything further about it.* 



The Common Flea (Pulex irritans, Linn.) — 

 Most of us are so well acquainted with this in- 

 sect in its perfect state, that it is not worth while 

 to dwell upon its peculiarities. It is not, how- 

 ever, so generally known that its larva is an 

 elongate, wriggling worm, totally unlike the 

 mother insect, and that it feeds upon particles 

 of clotted blood deposited along with the egg 

 upon the floor of apartments by the mother flea. 

 Hence fleas cannot multiply in a room where the 

 floor is conliinually scoured and swept; and 

 hence, also, we may deduce the practically im- 

 portant corollary, that the modern practice of 

 laying down a permanent carpet in bed-rooms, 

 instead of the old-fashioned bedside carpets, 

 which used to be taken up every few days and 

 shaken in the open air, affords decided facilities 

 for the propagation of the flea. 



Entomologists dift'er as to whether the fleas 

 ought to be placed in a small order by them- 

 selves (Ajyhaniptera) , or whether they should 

 form an abnormal family of the order of two- 

 winged flies {DixJtera) . As they agree in almost 

 every respect with the two-winged flies, except 

 in having but the merest rudimeuts of wings, 

 the latter seems the preferable course. After all, 

 these questions are questions rather of words than 

 of things, and of taste rather thmi of science. 



It is commonly supposed that the flea that in- 

 fests the dog is the same species as that whicli 

 infests man; and that, consequently, dog-fleas 

 can exist, flourish, and multiply in bed-chambers 

 where there are no dogs. All entomologists, 

 however, are agreed that each species of flea is 

 peculiar to a distinct species, or at all events to 

 a distinct genus, of animals ; and we have de- 

 scriptions of some ten distinct fleas, inhabiting 

 respectively man, the dog, the cat, the squirrel, 

 the hedgehog, the mole, the mouse, the bat, the 

 Australian porcupine (^Echidna), and the do- 

 mestic fowl. AYo have ourselves found a small 

 species upon the young of the common raccoon. 



» Sec on this curious subject Say's works, II. , pages 32-38 



i 



