10 



enters (according to my idea) into the wound with its sharp cavity, and the 

 mosquito sucks through it the blood, which ascends alongside and between the 

 little setae into the belly of the mosquito." * The apical opening of this inner 

 sheath he correctly thought to be turned toward the ventral side. 



LEEUWENHOEK next endeavored to settle the structure of the proboscis of 

 Culex. All that I know of his work is from what Reaumur 12 (13 h memoire, 

 t. 4, p. 401-403) says of it. Leeuwenhoek found only four setae in the sheath 

 of the proboscis, and doubted that the inner sheath, described by Swammerdamm, 

 existed as a closed tube. BARTH, 13 on -the other hand, in 1737, according to 

 Reaumur (1. c., p. 403), thought the inner sheath was a closed tube and not a 

 channel. 



REAUMUR, 12 in 1738, published his description of the mouth-parts of Culex, 

 and of their mode of biting; to the latter subject he gave much attention, and 

 was the first to describe correctly how the sheath was disposed of during the 

 use of the setae within, in the act of biting. He also calls attention to the 

 poisonous effects of the bite, and, contrary to the views of Leeuweuhoek, who 

 thought the inflammation following the bite of Cule,r was due to the peculiar 

 nature of the wound itself, that is, that they were the natural consequences of a 

 wound made by an instrument of a particular form, Reaumur regarded the sub- 

 sequent inflammation of the place bitten by Ctde.r to be due to a poisonous liquid 

 which the insect injects into the wound, in order to cause the blood to flow 

 faster. Reaumur found only five of the six setae which the proboscis contains. 

 He favored the idea that the inner sheath, which Swammerdamm had described, 

 was not cylindrical, but only a channel open on one side. Reaumur also arrived 

 at the idea that the maxillary palpi of Cule.r could, in some cases, help to form 

 the sheath which encloses the setae, but he does not clearly say that they always 

 do so in the males. 



Since Reaumur's time but little has been added to our knowledge of the 

 mouth-parts of Culex, some writers following the statements of Swammerdamm, 

 others those of Reaumur, or of Leeuwenhoek, in regard to the number of setae. 

 Among others I will cite Sulzer 14 (176J), who says "four to five pointed tubules;"** 



* 



* "Ich halte davor, diese fiinf Angelgen dienen dazu, als mit so viel spitzigen Pfriem- 

 gen die Oeft'nung in den Schweisslb'chern der Haut zu machen. Wenn dass gethan, so 

 ziehen sie sich wiederum in die innere Scheide zuriick. Diese dringt dann (nach meinem 

 Begriff) mit ihrer spitzigen Hb'hle in die Wunde hinein, und die Miicke saugt durch sie das 

 Blut in sich, das neben und zwischen den kleinen Angeln bin in den Bauch der Miicke 

 hinaufsteigt." 



** "45 spitzigen Rohrchen." (p. 169.) 



