568 



SCIENCE 



[N. S. Vol. XXVIII. No. 721 



flies, and secondly, of a study of the abun- 

 dance of flies and their connection with the 

 spread of intestinal diseases of man, and what 

 proportion of these diseases were due to the 

 agency of the common house fly. 



The investigation was carried on primarily 

 to obtain evidence for the Committee on 

 Pollution of the Merchants' Association of 

 New York, that unsanitary conditions existed 

 and that these conditions were directly re- 

 sponsible for the prevalence of certain in- 

 testinal diseases of man; so that the said com- 

 mittee would have some basis for complaint 

 to the proper authority against the open 

 violation of the health laws by the citizens of 

 the city. The inspection of the water-front 

 (pp. 8-16) revealed large quantities of both 

 human and horse excreta exposed to fly in- 

 festation on piers, along the beach, and so 

 forth, as well as sewage and refuse matter of 

 all kinds; in a word an abundance of decom- 

 posed matter and fllth suitable for the breed- 

 ing place of flies, and swarming with the 

 latter and their young. 



Having obtained evidence by means of in- 

 spection that the forementioned unsanitary 

 conditions existed, and that flies were breed- 

 ing in and frequenting the fecal matter ex- 

 posed to them, an investigation was also con- 

 ducted by means of fly traps placed in various 

 parts of the city, to determine what bearing 

 the products (flies) of these conditions had 

 upon the actual transmission of intestinal 

 diseases within the city. 



The traps near unsanitary points caught 

 the largest number of flies, showing that these 

 conditions attracted them; those in cleaner 

 portions of the city caught but very few. The 

 flies caught in the traps were counted each 

 day and tabulated by weeks. The weekly 

 totals are then compared by means of a table 

 (p. 17) with the weekly totals of deaths in 

 the city from diarrhoeal diseases, showing 

 parallelism; this is further brought out by 

 means of two diagrams (facing p. 14) show- 

 ing the coincidence of the maximum abun- 

 dance of flies and of that of the intestinal 

 diseases of man. Still another diagram (fac- 

 ing p. 12) gives the curves of temperatures. 



representing fly activity, and of typhoid fever 

 and other intestinal diseases, for a period of 

 the flve preceding years, again showing almost 

 exact parallelism. Two maps (maps Nos. 1 

 and 2) are also introduced as further evi- 

 dence, showing the location of the individual 

 cases of typhoid fever in the Borough of Man- 

 hattan (map number 1) for 1904, and the loca- 

 tion of deaths from intestinal diseases for the 

 same area during 1906 (map number 2), and 

 they emphasize the fact that the great ma- 

 jority of the cases of sickness and of death 

 were located at those points found to be most 

 unsanitary in 1907; that is to say, were dis- 

 tributed over the fly-breeding area. A few 

 other minor corroborative facts are recorded, 

 such as the finding of numerous pathogenic 

 bacteria on the appendages of flies during the 

 breeding season, and but little or none at all 

 on them just following hibernation. The con- 

 clusion indicated is obvious, but I quote the 

 author's concluding paragraph (p. 19) : 



It is to be hoped that the gross defects which 

 we have pointed out in general sanitation as well 

 as in sewage disposal will be remedied before the 

 summer of 1908. We have estimated that proper 

 sanitation along the lines pointed out will reduce 

 the typhoid deaths in New York from 650 to 360 

 a year and the diarrheal deaths from 7,000 to 

 2,000 a year. This latter figure provides that 

 germ-infected flies are not permitted to contam- 

 inate the milk supply before it reaches the city 

 or after. This saving of over 5,000 lives a year 

 will also be accompanied by the additional saving 

 of some 50,000 cases of sickness. 



While the report establishes no new facts 

 in regard to the transmission of diseases by 

 flies (Musca domestica Linnseus), it is an im- 

 portant expose of actual conditions existing 

 in our most crowded city, and is corroborative 

 of previous investigations; besides, it brings 

 out the possibilities of lessening deaths and 

 sickness due to the agency of house flies by 

 proper sanitary measures. 



As a contribution to science, the report is 

 very poorly presented; it suffers especially 

 from lack of arrangement and will give 

 trouble to the bibliographer. No new bio- 

 logical facts are recorded about the common 

 house fly, and the author apparently does not 



