159 
1930] Orders of Insects 
1900 0 R L H C D Davenport 1900. 
1906 0 R C D H L Woodworth 1906. 
1908 0 R L C D H Osborn 1908, Daugherty 1912, San- 
derson and Peairs 1917. 
O H C L D R Froggatt 1908, Lefroy and Hewlett 
1909. 
1920 O R H L D C Crampton 1920. 
1921 O C R L D H Fernald 1921, Lefroy 1923. 
1923 O R H C L D Martini 1923 
1925 O R L C H D Imms 1925. 
1926 O R C H D L (Swammerdam) Tillyard 1926. 
Only three authors had great influence on the arrange- 
ment of the orders. Linnseus separates those with thick- 
ened front wings : probably he also appreciated the coordi- 
nated thoracic structure, the large movable prothorax in 
one group and the consolidated thorax in the other. 
Fabricius combined the three mandibulate orders and the 
three haustellate, and finally Oken grouped together the 
four orders with complex metamorphosis and within this 
group the three dominant orders were brought together. 
He also maintained the proximity of the members of the 
Linnsean group with consolidated thorax. 
These three men all antedated Darwin so that the ar- 
rangements in no case expressed any idea of phylogeny, 
and many later students probably adopted one arrange- 
ment or another without seriously considering questions of 
origin or development. The first evolutionist to suggest 
a new arrangement was Dana who adopted the sequence 
used by Ray and the last Tillyard adopted that of Swam- 
merdam. Thus the arrangement that suited the sense of 
fitness of these great pre-Linnean naturalists corresponds 
with the ideas of students of phylogeny. Indeed, the gen- 
eral thought has been that the historic groupings, or at least 
some of them, were essentially natural. 
The most decided trend after the days of Darwin has 
been towards the groupings of Linnaeus and Oken and away 
