XV111 PREFACE. 



we have to do are not alluded to, yet we may be sure they 

 were classed by him under his second order Aptera, and 

 which, although containing an heterogenous assemblage of 

 insects of very different habits and economy, but agreeing 

 in the one character of being wingless, we find adhered to 

 in the subsequent systems of Swammerdam, Linnaeus, De 

 Geer, Clairville, Cuvier, Kirby, &c : in other systems it 

 forms the basis, although different terms are employed. The 

 first attempt at figuring or enumerating species occurs (I 

 believe) in Hooke's Micrographia, 1665, in which is a good 

 plate of Pediculus Humanus. In 1685, Swammerdam's 

 " Biblia Naturae " appeared, containing elaborate anatomical 

 details of the same insect. Redi, in 1688, produced his 

 " Esperienze Intorno alia Generazione Degl' Insetti," with 

 thirty-four figures of the Lice of Mammalia and Birds. In 

 1736 Albin published his " Natural History of Spiders, and 

 other curious Insects," wherein are figures of all those spe- 

 cies given by Redi. From 1761 to 1781 appeared the 

 Systema Naturae, and Fauna Suecica of Linnaeus Sco- 

 poli's Entomologia Carniolica Geoffrey's Histoire abregee 

 des Insectes O. Fabricius's Fauna Grcenlandica Fabri- 

 cius's Systema Entomologiae, and Species Insectorum, with 

 one or two other works of less note, in all of which are enu- 

 merated or described several species of Pediculus^ for up to 

 this period no writer appears to have considered a separa- 

 tion necessary of the Mandibulata from the Haustellata, 

 but all were united under the Genus Pediculus. In 1783, 

 however, De Geer in his <c Genera et Species Insectorum," 

 attempted a revision, and divided the skin-eaters from the 

 true blood-sucking Lice, under the generic name of Ricinus. 

 Panzer and Clairville, however, who followed soon after, 

 retained the old grouping of such different organizations 

 under one Genus. In 1804 Dr Hermann produced his 

 " Memoire Apterologique," in which he recognized a dis- 

 tinction similar to that established by De Geer, but gave 



