MALARIA TRANSMITTERS 203 
where Anopheles quadrimaculatus had its breeding-places, but was absent from 
districts where A. punctipennis 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 punctipennis is the abundant species malaria 
is practically unknown ; while within the range of A. 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 
punctipennis 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 puncti- 
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. J. Lemann: Bionomics, experimental investigations with Bacillus 
sanarelli, and experimental investigations with malaria, in connection with 
the mosquitoes of New Orleans. N. Orl. Med. & Surg. Journ., 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 estivo-autumnal fever. On the other hand Anopheles crucians proved 
to be the bearer of estivo-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 estivo-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. listoni. “ 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 listont is generally more 
abundant in mountainous regions than on the coast and the distribution of 
tropical malaria corresponds. Taihoku, where A. listont does not occur, is there- 
fore free from the tropical malaria.” 
