THE century's WORK AMONG THE ACULEATE HYMENOPTERA. 13 



Two books lie before mo (Fabricius's supplement to his Kntomo- 

 loi^ia Systematica, 1798, and an anonymous Epitome Entamoltu/iae 

 Fahricianae, Leipzig, 1797), which may perhaps be taken to represent 

 the stock of knowledge at the commencement of the century. These 

 between theiii enumerate twenty genera of aculeates for the Avhole 

 world, viz., five bees, two wasps, two ants, and nine fossores. How 

 many genera are actually known at present in these four groups I 

 cannot say precisely, but, combining v. Dalla Torre's Catalogue, 1897, 

 with Kohl's Spheniden-Gattungen, 1896, I arrive at a total for the last 

 of them — the fossores — of 120 described genera ; while of bees 

 we know 28 genera from England alone (Saunders, 1896), and about 

 40 from Europe ; of Avasps, 3 genera from England and nearly 

 20 from Europe ; of ants, 12 from England and about 40 from 

 Europe. How many exotic genera might be added to swell these 

 figures I dare not even conjecture, but enough has been said to show 

 how immense has been the progress since Fabricius's times. 



The writers who have contributed to the result are innumerable, 

 and must mostly be here passed over in unmerited silence. We can 

 boast, however, in this country of one author, the Rev. William Kirby, 

 {Mun. Apum A}i(jliae, 1802), to whom students of the AntJtoph'da 

 (bees) owe a debt that can never be forgotten. He first 

 detected and described (unluckily without " naming " them) by far 

 the greater part of the groups and genera still recognised. A little 

 later (1807) Jurine greatly advanced the classification of all hymen- 

 optera by introducing his neuration-system, which still in the main 

 holds the field, though it can no longer be employed as the sole 

 criterion for distinguishing genera. Thomson's Hijmenoptera 

 Scandinaviac (1872-1874), Dahlbom's Sphex (1843-1845), and the 

 works of many living authors, Kohl and Handlirsch (fossores), de 

 Saussure (wasps), Perez, Schmiedeknecht, and Friese (bees), Mayr, 

 Forel and Emery (ants), must be mentioned in any list, however 

 short, of books which have really advanced our knowledge of the 

 aculeates. Lepeletier de St. Fargeau's work on the hymenoptera 

 is now of little use to stulents, but in its day it was of value, and it is 

 far too famous to be left unmentioned here. 



As to the travellers abroad and the workers in museums, itc, who 

 have raised the number of known species year by year throughout the 

 century, I can say only that their name is legion. Nor can I attempt 

 to reckon all the monographs (often valuable) of the aculeate-fauna 

 in particular districts — Morawitz was one of the most eminent workers 

 in this field, and Schenck, Costa, Dours, etc., are names that suggest 

 themselves in the same connection. Other monographists have 

 elucidated with more or less success particular, genera. It is almost 

 useless to give names, but I may mention a few which have helped 

 me while arranging my own collections, such as Forster {Prosopis), 

 Gerstaecker {Xylucopa, &c.), von Hagens (SpJiecudes), Schletterer 

 (Cerceris), Vachal, Ducke, &c., besides others already named m the 

 present paper. 



The microscopic anatomy of aculeates has been studied in this 

 century, and results of considerable interest have been attained, by 

 Dufour, Lacaze-Duthiers, Janet, Lubbock and others. On their 

 habits and instinct we have been enlightened by the charming popular 

 works of Huber, Fabre, and Lubbock, whilst Shuckard and Smith have 



