THYSANOURA, PARASITA, SUCTORIA. l65 



These insects remain by preference under the wings, about 

 the axilla, and on the head of birds; they attach them- 

 selves there very strongly, by means of the two robust and 

 equal crotchets which terminate their tarsi. They multiply 

 there sometimes, in such quantities, that the birds grow con- 

 siderably thinner, and may even die in consequence. Care 

 should be taken to examine domestic birds, supposed to be 

 infested by these vermin, and often to clean out the places 

 in which they are kept, and where they are accustomed to 

 rest. By such means they may also be protected from a 

 species of mite, which multiplies prodigiously in such places, 

 and by which these domestic animals are seriously incom- 

 moded. 



The genus of the ricini is very numerous ; there is na 

 bird without one or two species, Redi has figured a great 

 number of them, and though his figures are rude, one may 

 easily see how many varieties the forms of those insects pre- 

 sent. Their characters, manners, &c., are, with the excep- 

 tions already stated, the same as those of the lice. There is 

 one singularity in the ricinus pavonis, and that is, that the 

 antennae are forked. 



We now arrive at that well known genus, which consti- 

 tutes the order Suctoria, the Pulex, or fleas. In dividing, 

 as M. de Lamarck has done, the insects which undergo meta- 

 morphosis, into two grand sections, those which have mandi- 

 bles and jaws, and those in which these organs are transformed 

 into suckers, the order Suctoria seems to be intermediate 

 between the Hemiptera and the Diptera. 



If a certain number of female fleas be shut up in a vessel, at 

 the time in which they begin to appear, someone among them 

 will immediately commence to lay. They lay almost a dozen of 

 eggs ; these eggs are tolerably bulky, ellipsoid, white, and 

 somewhat clammy. Rcesel pretends that the mother lets them 

 drop at hazard : but it is probable that she attaches or glues 



