574 A CENTURY OF PROGRESS IN THE NATURAL SCIENCES 



better method of analyzing and making known the composition of the better- 

 collected faunal districts of the world. As each increment of information of a 

 particular group or region was added to the fund of knowledge, the total bio- 

 geographic picture commenced to emerge. 



In 1882 Alexandro Mocsary published a comprehensive world list of the lit- 

 erature pertaining to the order Hymenoptera. This was followed a few years 

 later by the appearance of Dalla Torre's Catalogus Hymenopterorum (1892- 

 1902), a work which provided a stimulus for the more exhaustive monographic 

 treatments which were to follow. More attention began to be directed toward 

 accumulating more detailed information on the distribution and biologies of 

 certain groups of wasps. Unfortunately little effort seems to have been made 

 toward tying together all the available information on any one group. As new 

 frontiers of the world were opened, largely through improved methods of trans- 

 portation, so many new species were being collected that the taxonomist devoted 

 a large share of his time to providing names. 



In America, Thomas Say was chiefly responsible for initiating the descriptive 

 phase in this country. Ezra T. Cresson (1863) brought together in his catalogue 

 the described species of North American wasps. Cresson led the way in com- 

 mencing an exhaustive study of the wasp fauna of North America. Similar in- 

 vestigations had preceded these — principally in England, France, and the Ger- 

 man countries. The results of the European studies, as well as the influence of 

 their workers, largely guided American thinking in matters of classification, 

 phylogeny, and biology. By 1887 Cresson had presented a synopsis of the North 

 American families and genera. At the turn of the century Ashmead re-examined 

 the existing classifications and made an attempt to synthesize the existing knowl- 

 edge relating to the phylogeny of the Hymenoptera. Other workers, such as 

 Viereck in America, Andre in France, Cameron in England, and Bischoff in 

 Germany, began to shape the broad outlines of the next twenty-five years of re- 

 search on the wasps. In general, the lower categories, particularly on the generic 

 level, were accorded a more thorough and virtually monographic treatment. This 

 approach was, to be sure, closely correlated with advances in the related sciences 

 and the improved technological equipment at their disposal. 



Perhaps the most significant contribution to the knowledge of the aculeate 

 wasps made during the present century has been the application of the prin- 

 ciples stemming from the theory of evolution. While it is yet too early to deter- 

 mine the total effect this will have on the analyses and evaluations of problems 

 dealing with biogeography and phylogeny, it is apparent that it will be profound. 

 The present trend of study has assumed the form of synthesis of the various 

 branches of knowledge so that the emerging interpretation of the aculeate 

 fauna is directed toward reflecting the equivalency expressed in nature. This 

 method seems best to achieve the ideal representation of the facts concerning 

 the origins, phylogenies, ecologies, and the role of the wasps in nature. 



In order to accomplish this interpretative representation it might be w^ell 

 first to re-examine more closely the present outlook on the basis of the probable 

 world aculeate fauna. The recent catalogue of Nearctic Hymenoptera lists ap- 

 proximately 3,500 species and infraspecifics from an area representing nearly 

 one-sixth of the earth's surface. Allowing for compensating changes in status, 

 synonymy, and description of new species, as well as taking into consideration 



