414 MAJOR W. S. PATTON. 



But my main reason for publishing these notes is to draw the attention of medical 

 and veterinary officers, and others, to the importance of collecting more material, 

 for in spite of the many thousands of specimens which I have examined, I have rio 

 hesitation in saying that my revision of the genus will not be as complete as I should 

 like it to be. I would, therefore, earnestly appeal to all who have opportunities 

 of collecting species of Musca to send them to me at the Zoological Department, 

 Edinburgh University, or to Dr. Guy A. K. Marshall, C.M.G., Director, Imperial 

 Bureau of Entomology, British Museum (Natural History), Cromwell Road, when 

 sending other entom.ological material ; T shall be glad to exchange any Indian species 

 for others. 



As many of the types of the older writers, such as those of Robineau-Desvoidy 

 and Macquart, are either lost or in very bad preservation, it is most important to 

 try to secure specimens from the localities from which their types were obtained, 

 and the localities will be mentioned in these notes. In order to facilitate the collec- 

 tion of this material, it ma.y be useful to give some notes on the species as a whole, 

 and also to indicate the special lines along which the collecting should be carried out. 



For ]:>ractical purposes, the species of the genus Musca fall into two natural 

 groups as follows : (1) The house-fly group, and (2) the wild species group. 



(1) The House-fly Group. 



In this gi'oup are included all those species which are cosmopolitan in habit, but 

 are mainly found in and around human dwellings, on food in bazaars, about butcheries, 

 offal, rubbish of all kinds and night-soil trenches. The four important species are 

 Musca domestica, Musca domcstka (atypical), Musca nebvdo and Musca humilis. 

 The first is the common European house-fly and the t3.'pe of the genus, and M. domestica 

 (atypical), M. nehulo and M. humilis are the important tropical and subtropical 

 species. Specimens of this type of house-fly are urgently wanted from as many 

 localities as possible. Musca humilis is a very characteristically marked species, 

 and can be easily recognised ; but when we come to Musca domestica (atypical) and 

 Musca nebulo it is not possible at present to give a definite opinion regarding them. 

 A series of specimens from the different ports as well as specimens from inland towns 

 must first be available for microscopic study. Specimens taken in copula would 

 be most useful. Larvae and flies hatched from them are the best material for 

 comparative study. If the observer lias not the time to pin the specimens they will 

 do equally well if they are placed in match-boxes without any cotton- wool. Such 

 specimens are quite suitable for the study of the external genitalia. 



In collecting these species it is important to note exactly where the specimen? 

 were caught, whether on food, indoors, or in bazaars ; and in this connection it 

 should be noted that this type of Musca may be seen on cattle and horses in company 

 with specimens of those of the next group. There should be no difficulty in collecting 

 the larvae of the house-fly in any locality. When mature they should be placed in 

 some earth in a cigarette tin, the lid of which is perforated with small holes, and 

 allowed to pupate. At the same time some specimens should be preserved by dropping 

 them into boiling water in a test-tube, and then placing them in a tube containing 

 70-80 per cent, alcohol. As soon as those in the tin have pupated, the puparia 

 should be collected and placed in dry tubes, and 36 hours after the f.ies have hatched 

 out they should be pinned along with their puparia ; the latter are most useful in 

 correctly associating the larvae with their respective adults. A good series of males 

 and females collected in thi^ way would be most valuable for comparative study. 



(2) The Wild Species Group . 



Some years ago I drew attention to the peculiar habit of Musca pattoni, Austen, 

 which feeds on the blood that exudes from the punctures made by biting flies, 

 and on the serous fluid which exudes from cuts, sores and particularly from cowpox 



