(107) 



348 C. GORDON HEWITT. 



PAGE 



5. Ophthalmia . 399(158) 



6. Plague . . ,. . . .401 (160) 



7. Miscellanea . 402(161) 

 VIII. Flies and Intestinal Myiasis . . . . .404 (163) 



IX. Literature . . . . . .405 (164) 



X. Appendix on the Winter Breeding of M. domestica . 412(171) 



I. INTRODUCTION. 



THE present paper concludes this study of the structure, 

 development, and bionomics of Musca domestica (the 

 previous parts were published in 1907 and 1908). In it I 

 have described the bionomics, certain of its allies which may 

 occur in houses, its parasites, and its relation to man, especially 

 as the carrier of the bacilli of certain infectious diseases. 



The last portion of the present paper, in which is described 

 what is known concerning the ability of M. domestica and 

 its allies to carry and disseminate the bacteria of many impor- 

 tant diseases, shows, I hope, the grave character of its relation 

 to man. Although its importance in this respect is being 

 gradually realised in this country, it is not so widely recog- 

 nised as it should be. In the United States of America it is 

 proposed to change this insect's name from the house-fly to 

 the " Typhoid fly " ; notwithstanding certain objections to this 

 name, it clearly indicates that more attention must be paid to 

 preventive measures, that is, they must be reduced by the 

 deprivation of suitable breeding-places. I have not discussed 

 in the present paper the relation of house-flies to infantile or 

 summer diarrhoea, chiefly because we are not yet certain as to 

 the specific cause, but this disease may be included for the 

 present under typhoid or enteric fever in so far as the relation 

 of flies with it is concerned. 



I should like to take this opportunity of thanking those 

 medical men, whose names I mention later, for the kind 

 manner in which they have replied to my inquiries concern- 

 ing their observations on various diseases of which they have 

 special knowledge. 



