232 
ten been overiooked by later naturalists. 
Swammerdamm determined correctly the 
number of setae in the proboscis of 
the female, but he, erroneously, evidently 
supposed that the proboscis of the male 
had the same number of setae as that of 
the female. He erroneously thought 
the setae to be capable of protrusion 
from the end of the sheath, without flex- 
ion of the latter, and that the largest of 
the five setae formed an inner sheath for 
the other four. He writes (p. 147) in 
quaint old style, ‘‘ I consider that these 
five setae serve, like so many sharp little 
awls, to make the opening in the sweat- 
pores of the skin. When this is done 
they are drawn back again into the inner 
sheath. This then enters (according to 
my idea) into the wound with its sharp 
cavity, and the mosquito sucks through 
it the blood, which ascends alongside of 
and between the little setae into the belly 
of the mosquito.” 
Leeuwenhoek, according to Réaumur, 
found only four setae in the sheath of the 
proboscis, and considered that the inner 
sheath, described by Swammerdamm, 
was a channel, and not a closed tube. 
Barth,* whose dissertation I have lately 
examined, thought the inner sheath was 
a closed tube. Réaumur,? in 1738, pub- 
lished a long description of the mouth- 
parts of Culex, and described with great 
accuracy its mode of biting. Réaumur 
found only five of the six setae which 
the proboscis contains. He favored the 
idea that the inner sheath, which Swam- 
merdamm had described, was not cylin- 
4 Barth, Jj. M. Dissertation de culice ... 1737. 
5 Réaumur, R. A. F. Mémoires pour servir a 
lhistoire des insectes. ... [Edition 1737-1748, t. 4, 
part 2.] 
PSTCHE. 
drical, but only a channel open on one 
side. Réaumur also arrived at the idea 
that the maxillary palpi of Culex 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 Réaumur’s time but little has 
been added to our knowledge of the 
mouth-parts of Culex, some writers fol- 
lowing the statements of Swammerdamm, 
others those of Réaumur, or of Leeu- 
wenhoek, in regard to the number of 
setae. Among others I will cite Sulzer,® 
who says, ‘‘four to five pointed tub- 
ules ;’ Fabricius,! who writes, ‘* sheath 
exserted, univalvular, flexible, with five 
setae ;’’ J6rdens’ describes four setae; 
Gravenhorst,® ‘‘ The proboscis long, seti- 
form, five-parted;” Meigen’ describes 
four setae and figures five; Gerstfeldt,” 
‘¢ The sheath is formed of the under lip 
alone, and contains ‘six setae;” Pack- 
ard," ‘* These six bristle-like organs are 
folded together within the hollowed la- 
bium;” Claus’ writes, proboscis ‘‘ ex- 
tended with four setae ;” Muhr’™ figures 
six setae. 
6 Sulzer, J.H. Die Kennzeichen der Insekten... 
1761. 
7 Jordens, J. H. Entomologie und Helminthologie 
des menschlichen K6rpers ... 1801. 
8 Gravenhorst, J. L. C. Grundziige der systema- 
tischen Naturgeschichte ... 1817. 
9 Meigen, J. W. Systematische Beschreibung 
der bekannten europdischen zweifliigeligen Insekten 
. 1818-1838. 
to Gerstfeldt, G. Ueber die Mundtheile der sau- 
genden Insecten ... 1853. 
11 Packard, A. S., Jr. Guide to the study of in- 
sects, ... 1869. 
12 Claus, C. Grundziige der Zoologie .,. 1876. 
13 Muhr,]J. Die Mundtheile der Insekten dar- 
gestellt auf 5 Wandtafeln ... 1878. 
