MALARIA TRANSMITTERS 203 



where Anopheles quadrimaculatus had its breeding-places, but was absent from 

 districts where A. punciipennis abounded. Smith, in his report of the New 

 Jersey State Agricultural Experiment Station upon the mosquitoes occurring 

 within the State (1904, page 158), discusses the relation of Anopheles to malaria 

 in New Jersey. Where Anopheles punciipennis is the abundant species malaria 

 is practically unknown ; while within the range oiA. crucians malaria does occur, 

 it is by no means prevalent and A. quadrimaculatus is also found there and is 

 considered by him the responsible species. Dr. J. W. Dupree, however, has re- 

 corded the fact that the malarial relation has been established for Anopheles 

 punciipennis by himself. He further states that it has been established for 

 Anopheles crucians by Pothier and Beyer. 



The discrepancies in the results of different investigators, which are par- 

 ticularly obvious in the above-mentioned experiments with Anopheles puncii- 

 pennis, may find an explanation in facts brought out by Professor Beyer and 

 his collaborators (Prof. George E. Beyer, Dr. 0. L. Pothier, Dr. M. Couret 

 and Dr. I. I. Lemann: Bionomics, experimental investigations with Bacillus 

 sanarelli, and experimental investigations with malaria, in connection with 

 the mosquitoes of New Orleans. N. Orl. Med. & Surg. Joum., Jan., 1902). 

 These investigators show that a definite species of Anopheles can be the host of a 

 certain type of malaria while other types of malaria can not develop within it. 

 In a series of careful experiments it was found by these students that Anopheles 

 quadrimaculatus became infected with the parasites of tertian and quartan, but 

 not of ffistivo-autumnal fever. On the other hand Anopheles crucians proved 

 to be the bearer of sestivo-autumnal malaria while it remained wholly negative 

 to the other types of parasites. The results were obtained by feeding mos- 

 quitoes of both species upon humans in whose blood the malarial parasites were 

 found to be present, and, after a suitable interval, examining the mosquito for 

 the parasite. These experiments were repeated a sufficient number of times 

 with the different types of malaria and the two species of Anopheles to be 

 conclusive. They found further that the distribution of Anopheles crucians 

 about the city of New Orleans corresponded very closely with the distribution 

 of the cases of agstivo-autumnal fever. 



Kinoshita, in his studies in Formosa and Japan, found that the type of 

 malaria depends upon the species of Anopheles, and that, while in Europe 

 Anopheles maculipennis appears to be capable of transmitting all three forms of 

 malaria, this is not true of any of the Anopheles studied by him. In Formosa 

 the occurrence of pernicious malaria corresponds, both geographically and in 

 time, with the occurrence of A. lisioni. " Every epidemic of malaria tropica 

 depends upon the increase and decrease of A. listoni, of which, as determined 

 above, more than 50 per cent can transmit tropical malaria. This mosquito 

 develops very abundantly between the months of April and October. The new 

 infections of tropical malaria begin also about the end of April and reach the 

 highest number between June and July. Anopheles listoni is generally more 

 abundant in mountainous regions than on the coast and the distribution of 

 tropical malaria corresponds. Taihoku, where A. listoni does not occur, is there- 

 fore free from the tropical malaria." 



