872 KARM NARAYAN BAHL 
2. The Supra-intestinal Vessel.—The supra-intes- 
tinal vessel, which is confined to the oesophageal region 
behind the gizzard, occupies the same relative position with 
regard to the gut as the dorsal vessel does in the region of the 
intestine. It lies beneath the dorsal vessel rather closely 
attached to the dorsal wall of the oesophagus, while the dorsal 
vessel itself is removed considerably away from the gut. It is 
usually double along its whole extent, but the two halves come 
together and communicate with each other at several places. 
The supra-intestinal vessel extends from the tenth to the 
thirteenth segment. In the tenth and eleventh segments it 
communicates with the lateral oesophageal vessels by large 
commissural vessels or ‘loops’ that go round free from the 
wall of the oesophagus ; while in the twelfth and thirteenth 
segments it communicates with the ventral vessel through the 
‘hearts’. The vessel ends anteriorly by breaking up into 
capillaries in front of the tenth segment, and these capillaries 
are distributed over the walls of the oesophagus and the 
gizzard. Posteriorly the vessel ends by joining the posterior 
pair of ‘ hearts’ in the thirteenth segment, although a slender 
branch very often continues backwards on the mid-dorsal line 
of the gut for a segment or two. 
The supra-intestinal is the efferent vessel for the gizzard 
and the oesophagus, and all the blood brought in it from 
these structures is no doubt carried into the ‘ hearts’ of the 
twelfth and thirteenth segments. 
3. The Ventral Vessel.—The ventral vessel extends 
anteriorly up to the second segment, and in each segment 
gives off a pair of ventro-tegumentary branches as in the 
posterior region, with the difference that the branches from 
a particular segment are spread over and distribute blood to 
the body-wall, the septa, and the nephridia in the same 
segment and not the succeeding one, as they do behind. 
All the special organs in this part of the body, e.g. the sperma- 
thecae, the seminal vesicles, the ovaries, and the oviducts 
are supphed with blood by little branches from the ventro- 
tegumentaries. The vessel ends anteriorly in a pair of branches 
