500 ^ CENTURY OF PROGRESS IN THE NATURAL SCIENCES 



Class Labiata 



Order Collembola 

 Order Protura 

 Order Symphyla 

 Order Entotrophi 

 Section Amyocerata 



Class Thysanura 

 Class Pterygota 



Subclass Paleoptera 

 Subclass Neoptera 



The major division separates the Myocerata (with intrinsic antennal mus- 

 culature, no amnion and serosa, and no phallus or ovipositor of the type uni- 

 formly found in Thysanura and generalized Pterygota) from the Amyocerata 

 (lacking intrinsic musculature in the flagellar segments and possessing amnion 

 and serosa and the highly characteristic phallus and ovipositor). This division 

 necessarily splits a vertical series rather than two great groups equally remote 

 from the common ancestor. The Amyocerata are believed by most recent special- 

 ists to be descended from a form rather closely related to the Symphyla and 

 Entotrophi. As can be seen, it is not reasonable for entomologists and their text- 

 books to accept as their province the Collembola and Entotrophi, while rejecting 

 the myriapod groups. 



Collembola 



Sir John Lubbock, Lord Avebury, beginning ninety years ago, wrote a series 

 of important papers on the Springtails, in one of which he segregated them from 

 the Thysanura and gave the new order the universally accepted name Collem- 

 bola. In 1873 the Ray Society published his superb Monograph of the Colleni- 

 hola and Thysanura, in which all the published knowledge was assembled and 

 analyzed, with many original observations. Lubbock afterward concentrated his 

 interests on other groups of organisms, but he described a few subpolar species 

 of Collembola up to the end of the nineteenth century. 



At about this time the taxonomy of the Collembola began to expand, with 

 Tullberg's papers on species of Scandinavia, those of Renter for northern Eur- 

 asia, of Parona for the Mediterranean region, and of Packard for North America. 

 At about the turn of the century the description of new genera and species 

 was rapidly accelerated by several new workers, some of whom are still active : 

 C. Schaeffer, who wrote from 1891-1900 and specialized on the faunas of Ger- 

 many and subpolar regions; H. Schott, 1891-1931, many regions; G. H. Car- 

 penter, 1895-1935, many regions; J. W. Folsom, 1896-1938, America and the 

 western Pacific; V. Willem, 1897-1925, Europe; J. Carl, 1899-1906, Switzer- 

 land; E. Wahlgren, 1899-1920, subpolar regions; C. Borner, 1900-1932, many 

 regions; and AV. M. Axelson (later Linnaniemi), 1900-1935, northern Europe. 

 At this time K. Absolon first described many of the remarkable cavernicolous 

 Collembola. Much of the modern classification of the members of the order is 

 the result of Borner 's intensive studies. Willem likewise dealt with classifica- 

 tion and, particularly, morphology. Other prominent morphologists were R. W. 

 Hoffman and A. Lecaillon. The contributions of J. Uzel, Agnes M. Claypole, 

 and J. Philiptschenko on the embryology are among the most significant. The 



