96
" ensured it will be impossible to effectually carry out any measure of
" mosquito destruction with hope of success. I am preparing a special
" report dealing with this question which I shall forward separately."
264. Letter No. 116, dated the 17th July 1909, from Dr. Charles A. Bentley,
M.B., D.P.H., on Special Duty, Malaria Investigation Committee, Bombay,
to the Municipal Commissioner for the City of Bombay, re State of Wells,
private and public, within the area of Fort North.
" In accordance with the minutes of the Committee Meeting held on
"the 30th June 1909, I have the honour to draw your attention to the
"dangerous state of the wells, private and public, within the area of the
" Fort North. A careful examination has been made of 511 wells within
" this section with the following result :—
(1) 240 have been found to contain very numerous larvæ of
Anopheles Mosquitoes.
(2) 32 of these contain larvæ of Culex or Stegomyia in addition.
(3) A total of 83 wells have been found to contain larvæ of
either Culex or Stegomyia Mosquitoes.
" It is stated by a large proportion of house-holders that many of
" these wells are unused. In a few cases wells have been discovered whose
" existence was unknown to the present occupiers of the houses in which
" they were situated. Many occupants of houses with mosquito-infected
" wells complained of being troubled with mosquitoes, but few, if any,
" appeared to know that the source of their trouble was the open or
" improperly guarded well in the house itself. A certain proportion of
" wells are provided with wooden covers, but many of such covers are
"useless and in other cases there is evidence that they are frequently
" left open. A few wells have been found blocked up and in certain cases,
" particularly in the neighbourhood of Frere Road, wells have been treated
" recently with Pesterine and are free from mosquito larvæ.
" Species of Mosquitoes breeding in the Wells.—Among the 240 wells
" infested by the larvæ of Anopheles, nearly every one is found to
"be the breeding place of N. stephensi, a most dangerous carrier of
" Malaria. The few exceptions show the presence of M. rossi. It
" has been shown experimentally that this species of Anopheles can be
" readily infected with Filaria, and in all probability it is one of the agents
" in the propagation of Filarial Disease. In the course of the present
"investigation adult mosquitoes of this species, that have been caught and
" examined in order to test the possibility of their serving as carriers of
" Malaria, have been found to be very heavily infected with Eilarial
" embryos. In this connection it may be remarked that certain common
"species of Culex mosquito are known to be also concerned in the
"transmission of Filarial disease, and among the 83 wells which contain
" other than Anopheles larvæ Culex mosquitoes of this kind are to be
" found breeding. A certain proportion of the wells contain the larvæ
" of Stegomyia calopus (formerly known as Stegomyia fasciata), the
" species of mosquito concerned in the propagation of Yellow Fever in the
" Western Hemisphere.
" Malaria in the Fort.—Enquiry shows that Malaria has been present
" in the North Fort Section for many years, and a reference to past
" history reveals the fact that for generations this portion of the City
" has suffered from the evil effects of ' dangerous miasmata.' It is certain
" that Anopheles mosquitoes must have existed in this part of Bombay
" for a very long time and it is probable that their distribution has been
" extended from time to time. Por mosquitoes can be conveyed long
" distances in covered vehicles, etc., and they may frequently be found
"taking shelter in shigrams and the hoods of victorias. It appears
" probable that among the many carriages of all kinds which daily visit
" and sometimes remain for hours within the busy trading centre of
" Fort North, a large proportion carry away mosquitoes from the locality