TUK IJFE-IIISTOKY OF A LEl'IDOl'TEUOUS INSKl'T. 91 



it probable that the ancestors of insects were myriapod-like. If, 

 however, we weigh the great difference lietween the Crustacea on the 

 one hand and the rest of Arthropods on tlie other, a close relationship l)e- 

 tween Insecta and Ci'ustaceans appears simjily impossible. The Naupliw^- 

 form of larva, an exclusively Crustacean jtossessiou, the reniarkal)lc 

 resemblance in eniliryonic development between Insecta and Perijxitns, 

 and the constitution of the respiratory and excretory organs, are facts 

 wliich all compel us to conclude that the Arthi'opods are at least 

 diphyletic in origin. The Crustacea, indeed, are to be derived from 

 marine Annelids, which in the course of their develojjment passed 

 through the Trochosphere stage (which in the Crustacean development 

 became transformed into that of Naujih'us), while for the ancestors of 

 the Tracheata we must look to terrestrial or freshwater Annelids, more 

 of the Oligochtete ty2)e." All these theories are necessarily of an 

 extremely speculative nature ; the present state of our knowledge on 

 the subject, and the disconnected and scrap2)y information hitherto 

 yielded by geological research, do not, at present, furnish the materials 

 for any confident conclusions. 



G. Cn the antiquity of inse(;ts. — The fragmentarj' information 

 furnished by geology is sufficient to show that the Mammals, and in fact 

 the Vertebrates in general, of the j^resent day had no exact counterparts 

 in ancient geological times. The Eocene and Miocene Mammalia bore 

 but little resemblance to those now in existence ; the Saurians and flying 

 reptiles of the Oolitic period differ entirely from any existing animals ; 

 even the fishes of the Devonian and Old Ked Sandstone ages, have 

 scarcely representatives in our fauna of to-day. But this is not so 

 with regard to insects ; not only do the fossil insects which have been 

 found belong without doid)t to the well-defined Orders of Coleoptera, 

 Orthoptera, Neuroptera, Lepidoptera, etc., with which we are familiar, 

 l)ut palaeontologists refer the dragon-flies and beetles which evidently 

 existed in Mesozoic and Palaeozoic times even to the genera of to-day. 

 The great antiquity of insects has Ijeen proved most conclusively therefore 

 by geological research, but the various Orders are not equally abundant 

 in the oldest rocks ; the remains tend to show that whilst Neuroptera 

 and Orthoptera are probably the most ancient Orders of insects, Lepi- 

 doptera is among the newest, and it is supposed that this Order branched 

 off from the Neurojjtera about the commencement of the Tertiary period. 

 What the original stem form of the Lepidoptera was like has long been 

 a matter of speculation. Oppenheim refers certain fossils, found by 

 Hieberlein in the Solenhofer slate to an Order connecting Neuroptera 

 and Lepidoptera, and this has sometimes l^een looked upon as a probably 

 primeval ty})e, ])ut of Lejndojitera proper he considers Consuls to be 

 probably the oldest existing family. Dr. Walter looks upon Micropteryx 

 as the original lepidopteron, and Dr. Chapman has recently discovered 

 that this genus has species wliicli in the j)upa have functionally active 

 mandibles. Brandt, by a different process of reasoning, supports 

 Oppenheim's view, that Cossm is the oldest form. But the further 

 consideration of the various arguments which have led uj) to these 

 views would be out of place here, and I will only repeat again that 

 lepidopterists are mainly agreed that the Lepidoptera originated from 

 the Neuroptera, and that the early part of the Tertiary epoch saw the 

 first beginning of the Order. 



7. On fossil inskcts with i-iiotiiouacic wings. — It would be 



