REMINGTON: THE "APTERYCOTA" 501 



Collembola specialists who followed these men have been numerous. Some of 

 the most notable are: R. S. Bagnall, who concentrated on the species of Great 

 Britain and whose Collembola papers appeared from 1909-1941; E. Handschin, 

 1919-1942, many regions; H. Womersley, 1924-1942, British Empire; and M. 

 Kseneman, 1932-1938, Czechoslovakia. W. E. Collinge, W. M. Davies, and J. 

 Davidson wrote on the physiology and the economic importance of the Collem- 

 bola of Britain and Australia. There are many taxonomists contributing to the 

 current literature, among the most productive being the following ten. Jan 

 Stach has concentrated since 1919 on the species of eastern Europe and of caves; 

 at an advanced age he is writing a monumental work covering all the known 

 species (the first four parts contain over a thousand pages and 119 plates). J. R. 

 Denis, whose papers have appeared since 1921, has treated the French and Italian 

 forms and has written frequently on morphology of the Collembola; his section 

 on the Collembola, Protura, Entotrophi, and Thysanura is a high spot in the new 

 Traits de Zoologie (Tome IX). F. Bonet, now in Mexico City, has been writing 

 on Collembola of Spain, Latin America, and especially of caves, since 1928. J. 

 Agrell's papers on European species, appearing since 1929, have included not- 

 able works on the ecology of soil populations. H. B. ]\Iills has written, on the 

 North American Collembola in particular, since 1930; his Monograph of the 

 Collemhola of Iowa (1934) has long been the basic reference on the North Ameri- 

 can representatives. E. A. Maynard's Collemhola of New York State (1951) is, 

 like Mills's Monograph, applicable to a wider area than the title implies and in- 

 cludes interesting colored plates and a large bibliography. There are several 

 papers by F. Kos on Yugoslavian springtails. J. T. Salmon has specialized on 

 the Collembola of New Zealand and the nearest islands, with emphasis on their 

 biogeography. H. Gisin, a former student of Handschin, is one of the most not- 

 able contemporary specialists of the central European and holaretic Collembola. 

 C. Delamare-Deboutteville publishes regularly papers on the French species and, 

 most recently, on the African. Some other active younger workers are D. L. 

 Wray, K. C. Christiansen, Marie Hammer, and P. F. Bellinger. 



The Collembola are so small and so abundant that many are superbly pre- 

 served in amber. Handschin (1926) reported in the Baltic Amber only forms 

 similar to those now living. However, the much older Canadian Amber (Creta- 

 ceous?) contains a genus which Folsom named Protentomohrya and which seems 

 to be annectent between extant groups. The most interesting fossil form is Rhy- 

 niella praecursor Hirst and Maulik, from the Devonian- Rhynie Chert. The re- 

 cent restudy by Scourfield (1940) seems to show conclusively that Rhyniella is 

 a true collembolan. 



In spite of the bulk of literature, knowledge of this group is very incomplete. 

 Taxonomically, the Collembola are still relatively little known. Even in Europe 

 and North America the polytypic species concept is only beginning to be ap- 

 plied. The faunas of South America, of most of Asia and the Indies, of western 

 North America, and of much of Africa have hardly been sampled. Almost noth- 

 ing is understood of the natural history and physiology. Even the process of 

 fecundation of a single species of Collembola was not certainly known until 1952. 

 The embryonic development of a variety of forms needs to be studied by modern 

 zoologists. F. Carpentier and his co-workers have produced important new papers 

 on certain aspects of the morphology of Collembola, but otherwise all too little 



