886 



ScüDDER (1886), Bronuniakt (1894) and IIandlirscii (1 903, '06, '10). 

 Zittel-Broili (1915) ag-rees witli tlie latter in the niain points. 



ïhe number of fossil insects lias now bücome so considerable, 

 that the existence of a palaeo-entomology can no longer be denied. 

 The prineipal lines of tlie genealogical tree can already be drawn. 



Handlirsch (1908, p. 720 sqq.) directs attention to the fact, 

 that originally tlie abdomen consists of 11 segments and a telson, 

 the llth segment hearing a pair of cerci. 



In the Palaeozoic era there are only Ametabola ; all the different 

 Metabola appear at about the same time, namely in the Permian 

 formation. 



In the Palaeozoieum the relatives of the Polynephria are fonnd, 

 in Perm and Trias the Oligonephria appear. From the fact of 

 their synchronistic appearance it follows, that perhaps a poly- 

 phyletic origin of the higher orders may be assumed, which orders 

 therefore appeared as parallel lines. In the Perm the branch of 

 the Neuropteroided and that of the Coleopteroldea are already 

 separated from that of the Paiiorpoidea. To the latter belong the 

 Phry(ja}ioidea^ Panorpata, Lepidoptera, Snctoria and Diptera. This 

 classification ditfers entirely from that of Lameere. 



Handlirsch addnces against this writer (1900, p. 174): 



1°. The rednction of the cross-veins. Yery often the recent 

 holometabolic Neuroptera and SiaUdae still show a more original 

 vein-course than the carbonic Megasecoptera (the primitive group 

 of the Panoipoidea)^ besides the rednction of the veins is a 

 comnion featnre in Heterometabola. 



2°. The habit of carrying the wings in a horizontal position 

 is only fonnd in Heterometabola, these alone have well-developed 

 cerci ; the Megasecoj^terous-larvae also had wing-sheaths like that, 

 and therefore were probably heterometabolic too. 



8°, Tlie Lepidoptera are originally phytophagous and they only 

 become secondarily endophagous. In this case organisms would have 

 been drivcn in a progressive direction by the influence of parasitism 

 according to Lameere, whereas as a rnle they degenerate by it. 



4°. If wc adhere to a monophyletic origin of all Holometabola, 



