96 



yellow fever than was originally the case. In tropical America 

 numerous influences, economic and otherwise, by diminishing the 

 arrivals of susceptible Americans and Europeans have helped the 

 tendency to natural ehmination. Many places in which yellow fever 

 exists will need very Uttle sanitary work to turn the scale against it, 

 and the freeing of one place frequently prevents the infection of 

 another. 



Facts such as these justify the plan of the International Health 

 Board for the ehmination of yellow fever from the earth — the first 

 attempt to exterminate a micro-organism pathogenic to man. 



Blacklock (B.) & Carter (H. F.). The experimental Infection in 

 England of Anopheles plumbeus, Stephens, and Anojiheles 

 bifurcatus, L., with Plasmodimn vivax. — Ann. Trop. Med. Parasif., 

 Liverjwol, xiii; no. 4, 15th March 1920, pp. 413-420. 



Examination of the literature seems to show that there is no previous 

 evidence that Anopheles plurnbeus is an agent in the carriage of 

 malaria. 



Further experiments [R.A.E., B, vii, 160] show that it is not 

 difficult to infect A. phimbeus with Plasmodium vivax. At 28°C. 

 (82'4°F.) infections of the gut and salivary glands were obtained ; at 

 room temperature (max. 26°C. (78-8°F), min. 17°C. (62-6°F.) ) gut 

 infection only was obtained. In the case of A. bifurcatus gut infection 

 only was produced at 28°C (82-4°F). 



Blacklock (B.). & Carter (H. F.). Observations on Anopheles 

 (Coelodiazesis) plumbeus, Stephens, with special reference to its 

 Breeding Places, Occurrence in the Liverpool District, and possible 

 Connection with the Spread of Malaria. — Ann. Trop. Med. Parasit., 

 Liverp)Ool, xiii, no. 4, 15th March 1920, pp. 421-444, 3 plates. 

 2 maps. 



The synonymy of Anopheles plumbeus and its relationship with other 

 Anophehnes are discussed. An account is given of its distribution, 

 the characters and habits of the adult and immature stages and the 

 breeding-places (rot-holes in trees). Maps show the locahties in which 

 it is known to occur in the British Isles and in the Liverpool district 

 in particular. 



The authors are of opinion that A. plumbeus is worthy of serious 

 consideration as a natural carrier of malaria. In country districts or 

 woodlands frequented by the pubhc the possibiUty of its disseminating 

 the disease can be readily appreciated. But in towns or villages 

 away from large w^oods the extent to which it occurs can only be 

 decided by careful surveys for breeding places. 



The adult habit of resting in rot-holes in trees renders any conclusion 

 drawn from an adult mosquito census elsewhere entirely misleading, 

 and this may also cause the degree of its domestication to be underesti- 

 mated, since the insects would only stay in houses long enough to feed. 

 It is therefore desirable to investigate fully the immediate surroundings 

 of any house to which the occurrence of cases of malaria seems pecuharly 

 restricted, with a view to discovering the breeding-places of A. plumbeus. 



