116 INTERNAL ANATOMY OF INSECTS. 
both these opinions have some foundation in nature. 
When, in the Arachnida, we discover a lobular substance 
consisting of granules filling the whole cavity of the body 
and wrapped round the intestines, every one will see in 
it no small analogy to the epiploon which in insects per- 
forms the same function: but when, upon a further exa- 
mination, we detect certain vessels communicating with 
this substance and the intestinal canal*, the idea that 
these may be hepatic ducts, and this substance analogous 
to the iver, immediately strikes us as not improbable. 
Again: when we discover pairs of other capillary and 
tortuous vessels connecting with the intestinal canal either 
at the pylorus or below it‘, which in appearance strik- 
ingly resemble the bile-vessels which we so constantly 
find in insects, we seem warranted in concluding that they 
are of the same nature and use: but when a nearer in- 
spection enables us to detect the hepatic ducts just men- 
tioned in the scorpion, and we find that these capillary 
vessels in the spider are in a very different situation from 
those in insects which we suppose them to represent, it 
occurs to us as not unlikely, that their function may be dif- 
ferent. 
Let us now consider how the intestinal canal is cir- 
cumstanced in the two sections into which the Class 
Arachnida is divided; the Scorpionide, and dAraneide, 
In the Scorpions, this organ proceeds from the mouth 
to the anus without any flexure or convolution, so that 
its length is scarcely equal to that of the body‘; it is 
slender, and its diameter, with the exception of an irre- 
gular dilatation here and there, is nearly the same in 
its whole extent; the gullet is short; the stomach long, 
+ Treviran, Arachnid. t. 1. f. 6. v. > Tbid. n. 
* Ibid. t. ii, f. 24. 8. bid. f.6. BB. 
