Coxal Glands of Scorpio. 55 
for my larger publication, it is necessary briefly to describe 
them here, as their arrangement throws important light on 
the morphology of the coxal gland in Scorpio. A long coiled 
tube opens just behind the first pair of legs; it runs backwards 
among the muscles and nerves, free of connective tissue, then, 
bending forward again, ends near its external opening. ‘The 
proximal end of this long duct is occasionally found expanded 
into aspongy mass of branching and anastomosing tubules, 
which join with the similar mass of tubules from the coxal 
gland of the other side to form a barrier across the cephalo- 
thorax. Through this spongy mass the blood, flowing back- 
wards freely through the body, must filter. It is important 
to bear in mind that these tubules are simply a development 
of the ends of the ducts, and the whole may be dissected out 
free from the body without any entanglement of connective 
tissue or blood-vessels, which latter do not exist in Galeodes. 
I am inclined to think that the histology of this gland is 
not so simple as it appears at first sight, and that Macleod’s 
description® of it, though in the main correct, requires revision. 
I am not, therefore, as yet in a position to make any histolo- 
gical comparisons between the coxal gland of Galeodes and 
that of Scorpio. 
The gland opens in Scorpio, not on the first leg, as in 
Galeodes, but in exactly the spot where I have recently 
shown f{ that the coxal gland of the Chernetide opens, viz. on 
the posterior face of the coxa of the third leg. In Scorpvo 
this posterior face of the coxa of the third leg is fused with 
the anterior face of the coxa of the fourth leg. But this 
fusion is so far incomplete as to form a channel close up 
against the body ; this channel runs forward from the external 
opening of the gland, so that the excretory matters find their 
way to the exterior between the tips of the coxe of the third 
and fourth pairs of legs close to the sternal plate. In serial 
sections both the duct of the coxal gland, on its way to the 
chitinous channel thus formed by the fused cox, and the 
chitinous channel itself are very easy to find, and the fact that 
they have been missed by former investigators { can only be 
explained by the frequent tearing of the sections by fragments 
of hard chitin. 
Plate Il. fig. 1 shows the chitinous channel in section, 
while figs. 2 and 8 show the connexion of the duct of the 
coxal gland with this c!.annel. 
The duct of the gland is much coiled and forms a compact 
* Bull. Ac. Bruxelles (8) t. viii., 1884. 
+ Journ. Linn. Soc., Zoology (in press). 
t Quart. Journ. Micr. Sci. xxiv. p. 154. 
