INTKODUCTION. vii 



It is to be hoped that this Monograph will at least have 

 the result of inducing those who have the opportunity to 

 collect Tsetse-flies for the British Museum, pinning some 

 specimens on the spot and preserving others carefully in spirit ; * 

 this would enable very necessary dissections to be made of the 

 proboscis and other structures, including the male genitalia. 

 It would be particularly interesting to see whether the specific 

 distinctions described in Chapter IV. are supported by hidden 

 differences in the latter organs. 



One new species is described in Chapter IV., and, with the 

 exception of the type of Gl. palpalis, Rob.-Desv., which, as ex- 

 plained in the proper place, is probably no longer in existence, 

 I have been so fortunate as to be able to examine the types of 

 all the other species, so that the correctness of my identifications 

 may consequently be relied upon. To Prof. Fr. Brauer and 

 Herr Josef Bischof, of the K. K. Naturhistorisches Hofmuseum, 

 Vienna ; Dr. R. Gestro, of the Museo Civico di Storia Natural e, 

 Genoa ; Prof. E. B. Poulton, F.R.S., of the Hope Museum, 

 Oxford ; and Mr. G. H. Verrall, of Newmarket, all of whom 

 have with the greatest readiness allowed me to examine the 

 various types in their charge or possession, it is my pleasant duty 

 to express my grateful acknowledgments. My sincere thanks 

 are likewise due to Mr. L. R. Crawshay, who courteously allowed 

 me to examine a series of specimens of different species collected 

 by his brother, Captain Richard Crawshay, to whom I am 

 indebted for the interesting observations on Tsetse-flies in 

 British Central Africa, printed in Chapter VII., Appendix B. ; 

 to Prof. Poulton, who lent me certain specimens of Glossina 

 morsitans in the collection of the Oxford Museum, in addition to 

 the types of the three species described by Westwood ; and to 

 Dr. K. Griinberg, of the Konigliches Zoologisches Museum, 

 Berlin, who most willingly sent for my examination the whole 

 of the Tsetse-material recently collected by Dr. Schilling in 

 Togo-land, West Africa. As a result of my examination of the 

 specimens from Togo, I have been able to show that the true 

 Glossina morsitans, Westw., occurs in that country, which was 

 hitherto unknown. Whether or not Trypanosoma brucei, the 

 parasite of Tsetse-fly disease, is capable of being conveyed from 

 animal to animal by siDecies of Glossina other than this has yet 



* For directions as to the way in which Tsetse-flies should be 

 collected, see the author's pamphlet, — " How to Collect Diptera (Two- 

 Winged Flies)," — issued by the British Museum (Natural History). 



