536 A CENTURY OF PROGRESS IN THE NATURAL SCIENCES 



eggs of leafhoppers and was therefore introduced into the Hawaiian Islands to 

 control the sugarcane leafhopper. It is now a matter of historical record that 

 Cyrtorhinus mundulus brought the sugarcane leafhopper under control and 

 saved the sugar industry for Hawaii. 



Another important group of hemipterous insects is the subfamily Triatom- 

 inae. Triatoma bugs are the vectors of the American trypanosomiasis or Cha- 

 gas' disease. This disease of tropical America was discovered in 1909 by Chagas 

 and since that time many investigators have contributed to our knowledge of 

 the disease and its control. 



The modern period in systematic studies of the Hemiptera in the United 

 States was inaugurated by Uhler in the latter part of the nineteenth century. It 

 was carried on by Van Duzee, Barber, Blatchley, Heidemann, Drake, Knight, 

 Harris, Fracker, McAfee and Malloch, Hungerford, Hussey, Parshley, Torre- 

 Bueno, Sailer, and by a host of others. Elsewhere in the world outstanding work 

 was developed by Horvath, Schouteden, Poppius, Kirkaldy, Bergroth, Handlirsch, 

 Wagner, Lent, Kormilev, De Carlo, Hoberlandt, Blote, Carvalho, Brown, Bruner, 

 Costa Lima, Jaczewski, Lundblad, Mancini, and many others. 



It is difficult to anticipate trends, but a look into the future may not be out 

 of keeping at this point. At the present time it may be said that most of the 

 regions of the world have been explored fairly adequately, but that our funda- 

 mental classification, the phylogenetic scheme for the Hemiptera, is still not 

 entirely satisfactory. The basic division into Gymnocerata and Cryptocerata, 

 based upon whether or not the antennae are concealed, is quite artificial. There- 

 fore, we need a comprehensive phylogenetic study of the entire order and this 

 will undoubtedly develop out of work that is now in progress in various parts 

 of the world. Second, we need a collation of the regional works that have been 

 pursued by students in various museums in various parts of the world. At the 

 present time it is possible to go from one European museum to another, or 

 from an American museum to a European museum and find type specimens 

 standing under different names in each museum. The fact is that no one has 

 systematically compared these types and established the synonymy which is so 

 necessary before any really comprehensible classification can be established. 

 Finally, we need a modern catalogue of species and keys to the genera of Hemip- 

 tera for the world. Thus it might be said that the analytical part of Hemiptera 

 classification has been fairly well done but that tlie synthetic part — the bringing 

 together of all the information — remains to be done. Therefore it is clear that 

 the next century has a big, and perhaps the most significant, task ahead, namely, 

 to bring all of the scattered information together into a comprehensible whole. 



NEUROPTERA AND MECOPTERA 



F. M. Carpenter 

 Harvard University 



By 1853 the Neuroptera and Mecoptera were being investigated by a number 

 of well known entomologists. F. Brauer had published more than a dozen papers 

 on them, mostly dealing with life histories, and L. Dufour had made important 



