208 MOSQUITOES OF NORTH AMERICA 
feeding. The voracity of the animals is incredible. An ordinary Culez, after it 
has sucked its fill, flies away. These Anopheles, however, are not satisfied with 
this but continue to suck, making more room by discharging the surplus through 
the anus. At first they discharge the faces and intestinal liquid, but afterwards, 
drop by drop, pure blood follows. So, before it chooses to fly away, it flushes its 
digestive tract with three to four times the amount of bood which would have 
been necessary to fill its stomach.” 
Grassi, in Italy, was the first to study carefully the habits of Anopheles and 
his observations still stand unsurpassed. He believes that the normal food of 
Anopheles is blood, and, if they can find it, exclusively that of warm-blooded 
animals. They prefer the blood of mammals, but he found that sometimes they 
would, as it seemed with some reluctance, suck the blood of birds (poultry, 
sparrows and hawks). Grassi does not believe that there is a predilection for 
particular mammals, but that they are attracted in proportion to the size of the 
animal, the larger animals appealing more strongly to the olfactory sense of the 
mosquitoes. He found that frequently, when a man and horse were near each 
other, the horse would be bitten many times before the man was bitten at all. On 
the other hand, in the case of a man and rabbit, the man is generally attacked 
first. 
Grassi found that under proper conditions Anopheles will bite in the open, in 
houses and in stables. He states that in-malarial regions it very often happens 
that, in the evening, when persons are sitting at their doors, they are attacked 
by great clouds of Anopheles. He found that in the summer the Anopheles, 
after having procured a blood-meal within the house, seeks a hiding place 
outside where it can digest the food. It does not fly far but hides in the foliage 
near by and returns to the same place to obtain another meal of blood. During 
the day they remain quiescent among the herbage, upon the under side of leaves, 
selecting a spot where they are best protected from sun, rain and wind. 
Grassi found that in the winter the Anopheles sought shelter in houses and 
particularly in stables, and that, while with low temperatures they remained 
quiescent, if the temperature rose they would suck blood. The preference of 
Anopheles for stables has been repeatedly observed. Kinoshita, in Formosa, 
found Anopheles abundant in stables and he utilized these in his studies on 
malaria, for it proved that such Anopheles were all free of malarial parasites. 
Mihlens, in his studies of some malarial epidemics in northern Germany, made 
some interesting observations on the preference of Anopheles for stables. In 
the spring of 1907 and 1908, at Bant in the vicinity of Wilhelmshaven, he found 
the Anopheles preponderatingly in the warm stables of cattle and hogs, where 
they had hibernated. They were rare in the cellars of houses, while, on the con- 
trary, Culex were abundant in the cellars but rare in the stables. The Anopheles 
fed through the winter and showed a preference for the animals over man. The 
stomach contents of the Anopheles from stables were tested by the Uhlenhut 
process and it was found that they consisted of the blood of cattle or hogs, ac- 
cording to whichever animal they happened to have been associated with. As 
already pointed out by Grassi, two factors probably determine the preference of 
