Marshall—On the Anatomy of the Dragonfly. 
783 
muscles attached to it pull it back from the seminal receptacles 
and, having the other and larger anterior end in part concave, 
one would suppose that it would have to do with pumping the 
sperm out of the receptacle. 
Where the openings of the two seminal receptacles join there 
is a large cavity with a very much wrinkled and folded wall. 
This passes backward into a narrow passageway which extends 
posteriorly into the vagina. From a dorsal view this outlet 
appears to pass directly through the center of the chitinous 
collar hut it in reality passes ventral to his part (figs. 48 and 
54). A little posterior to the collar the passageway shows 
a slight enlargement (seen in figure 47, just posterior to). 
Both from an examination of traverse sections and from entire 
mounts of this part of the reproductive system the lateral walls 
of this passageway are seen to have a number of cuticular setae 
which extend inward from the wall on which they originate 
(figs. 47 and 54). 
A section through this wall (fig. 52) shows very thick epithe¬ 
lial and cuticular layers. The epithelium consists of long nar¬ 
row cells with ovoid nuclei. The inner two-thirds of the cuti¬ 
cular layer has a very marked lamellate structure, this is fol¬ 
lowed by a much thinner layer (stippled in figure) which was 
blue in the slides stained with haematoxylin; and, last of all, an 
inner transparent layer from which the setae arise. 
The use of these setae is not at all clear, and, as only one of 
my specimens contained sperm in these parts of the reproductive 
organs, it was impossible, if they had a special function, to 
arrive at any conclusion as to what this function was. The one 
specimen in which sperm was found showed that in this pas¬ 
sageway they were arranged in regular rows running in two 
directions (fig. 48). An examination of this surface with 
a high power showed that these strings of sperms corresponded 
fairly regularly to the spaces between the setae; this is shown 
in figure 53 where the small circular areas represent the setae 
cut transversely. Such an arrangement of the sperm would 
naturally follow its being forced between the setae but if this 
in any way .persists and has anything to do with some special 
