FOOD PREFERENCES 107 
towards an inquiline of our poultry-houses. And may it not be possible that, 
furthermore, in the marked intellectual diversity between Culex fatigans and 
Stegomyia fasciata there is reflected the primitive diversity between their re- 
spective hosts? It is certain, and no one will dispute me, that a mosquito must 
be more expert to persecute man than to persecute poultry, cats or dogs, as the 
case may be. And are not the rats and house mice, and, among insects, the re- 
pulsive roaches proof how much effect the daily association with ‘ homo sapiens’ 
has upon intellectual development and refinement? ” 
Culex erythrothorax occurs in Californian swamps exclusively among the tall 
reeds. Dyar found that “a person sitting on the bank was immune from their 
attacks, but among the reeds they bit viciously in the daytime.” These reeds 
were inhabited by numerous water-fowl and it is upon these that this species of 
Culex, without a doubt, normally feeds. Pet caged birds, in regions of mosquito 
abundance, are reared with difficulty, and young birds are often killed by mos- 
quitoes. 
There is reason to believe that many of the species of Aédes prefer mammalian 
blood. The females of the species breeding upon the salt marshes of our coasts 
migrate inland in large swarms and these journeys are very probably under- 
taken in search of mammalian blood. The ferocity of the mosquitoes in northern 
regions is remarked upon by all who have visited such regions. Linneus early 
testified to it from his Lapland experience. Many other authors could be cited. 
One of us (Knab) experienced it on the prairies of Saskatchewan. 
In the opinion of Knab the blood-sucking instinct is so strong and so pre- 
cisely adjusted to circumstances that it must be looked upon as a function of the 
greatest importance to the mosquito. In the case of Aédes spencerii, the most 
abundant species of the prairies of the northwest, Knab has observed that it has 
the habit of flying towards prominent objects. Under natural conditions upon 
the open prairies such prominent objects would always be some warm-blooded 
animal and this habit demonstrates a very fine adjustment on the part of the 
mosquito. 
Some writers have held that but few of the mosquitoes which are so numerous 
in far northern regions could obtain a meal of blood and therefore the blood- 
sucking habit could not be considered normal or important in the economy of the 
insect. This idea is based upon an erroneous conception of the fauna of these 
regions. In fact the northern countries in former times teemed with warm- 
blooded animals; it is only necessary to mention the great herds of bison, elk, 
deer and antelope. Today, where the former inhabitants have disappeared 
before the settler, they are replaced by horses and cattle, and there is sufficient 
testimony as to how viciously these are attacked. 
Galli-Valerio and Rochaz de Jongh, in their investigations upon European 
mosquitoes, noted that certain mosquitoes showed a preference to animals over 
man. One of them noted that in a locality in which he had always been bitten 
by many Aédes nemorosus when there alone, when another person and a white 
dog were also present these mosquitoes attacked and greatly worried the dog 
while the persons sitting near were spared. This was the more remarkable as 
the persons should have been preferred. on account of the dark color of their 
clothing. 
