'Dr. Hackett has recently reported some of his investigations into malaria in Russia. There they have none of the true malaria transmitters, only messeae and typicus. But there is much malaria there. There is according to him a great scarcity of cattle.

The same may be said of many of the districts which I visited in Roumania. There is much malaria, the three important transmitters are absent but it could hardly be said that there is a great scarcity of cattle. Most of the peasants appear to own at least one cow, every peasant has his pony and many of them have at least one pig. I found much interest in comparing the types of human habitations with the types of animal houses from the point of view of resting places for Anopheles maculipennis.

...

Professor Cuica and Dr Chelarescu demonstrated to me the very heavy mortality among the A. typicus which they use in their laboratory at the institute of Professor Ballif. Eighty to ninety per.cent. deaths over a period of ten days is about the average. If this finding compares favourably with what happens in nature than at first sight it would appear that it should be extremely difficult for typicus and messeae to maintain endemic malaria but when it is remembered that numbers over a hundred can easily be collected in a single bedroom it is not so difficult to understand. It could be explained by numbers alone. Dr. Hackett has shown that a dence [sic] population of typicus and messeae may maintain malaria in endemic form which can be explained by the absence of cattle; may it not be the case also that malaria may be maintained by the presence of numerous cattle which are so housed as to be less attractive to the mosquitoes than are the dwellings of the inhabitants?

Dr. Sicault of Morroco [sic] informs me that there they cannot induce var. labranciae to bite cattle, it is essentially and [sic] insect which selects man. The same line cannot be srawn [sic] for messeae and typicus with regard to animals. We know that in the laboratory both varieties feed readily on man. May it not happen in nature that these two varieties, while preferring perhaps the semi-dungeon like shelters under which some animals are housed, will select the habitations of man if he happens to be living in the same kind of dwelling which the insect prefers and which more closely fulfil its requirements.’