166 



clined to suppose that the mosquitoes suck or at all events are able to suck blood 

 very often, most probably almost once in the course of twenty-four hours. 



It is difficult to see the real blood-filling process; I have never seen the mosquitoes 

 suck on bright days; nor have I been able to see the process during night, most 

 probably because it was always too dark in the stables and the mosquitoes had 

 left their victims when light arrived. On the other hand, in the time from ten to 

 twelve evening, very often when I came into the stable, especially in the hog-pens, 

 I have seen almost all the pigs rub themselves against the boards of the stall; 

 this I have only rarely observed in day-time. On dark days in dark stables I have 

 further often seen or rather just been able to catch a glimpse of the sucking Ano- 

 phelines; curiously enough I have most often observed them on the eye-lids of the 

 cows; more than once I have tried to catch them while they were sucking but 

 this was always an impossibility; the cows moved and the mosquitoes darted 

 away. — I have not tried to determine the blood in the mosquito stomachs; I soon 

 learned to regard this as quite a superfluous investigation. Later on I learned that 

 already Muhlens "konnte das Blut mit der Uhlenhutprobe als Schweine- bez. 

 Rinderblul anweisen" (Martini \$2Q x p. 60). It may be added that the few speci- 

 mens which I have found in the latter part of October have never been red but 

 have had a yellow coloured abdomen not distended with blood. The blood-sucking 

 period lasts only till about 15 /ix. 



6. The mosquitoes are always remarkably indolent, and sluggish; when en- 

 tering the stable the observer gets the impression that the mosquitoes sit almost as if 

 glued to the ceiling and walls. I shall not here discuss the well-known position which 

 the Anophelines generally adopt in contradistinction to the Culicines; (see especially 

 Prell 1917 p. 242) but only once more emphasize the peculiar position when they 

 hang down perpendicularly from the cobwebs by only one claw of the forelegs. 

 The animals are quite motionless and do not alter their position for many hours; 

 the moment, however, the glass approaches the mosquito and the distance is dimi- 

 nished only a few inches we immediately see the hindlegs make oscillations and 

 often describe circles in the air; if then the vessel is not rapidly put over the mos- 

 quito it takes the wing; unquestionably the long outstretched hindlegs are used as 

 organs of feeling. 



At first I thought that the number of mosquitoes which I should find at night 

 hanging indolent from the ceiling would be smaller than by day; this may perhaps 

 really be the case but after all the difference is but slight. On l»/viu I marked the 

 resting places of 40 A. macnlipennis; time seven o'clock in the evening; the next 

 morning at nine o'clock twenty-nine of the mosquitoes had not altered their places. 

 I have got the impression that the females almost live their whole life in the cow- 

 houses, only fly out of doors to pair and for the purpose of egg-laying; on calm 

 evenings I have observed the mosquitoes from outside either fly through the open 

 door or against the windows, but I have never been able to observe a flight from 

 the stable into the open; Mr. Petersen writes to me that in the western part of 



