52 



52, Orb.V.). Just behind the origin of the funnel pro- 

 tractors are seen t%'70 veins from tlie muscles of the head, 

 and a single ventral vein formed by the union of two 

 running down the back of the funnel (fig. 52, F.V.). At 

 the level of the posterior edge of the funnel another branch 

 (Miters, which is formed by the union of branches from the 

 anterior surface of the visceral envelope and the posterior 

 dorsal funnel wall (fig. 52). Further back the anterior 

 vena cava receives a vessel dorsally from the antero- 

 ventral surface of the liver. This vessel also receives a 

 vein from the wall of the rectum. Yentrally, about the 

 same level, a pair of veins comes in from the funnel 

 depressors, receiving small branches from the visceral 

 envelope on their way. The next branch is from the 

 septal muscle, and is succeeded by another large vein 

 from the liver, entering dorsally, and draining the pos- 

 terior part of this organ. The final vessel which enters, 

 just before bifurcation, is from the intestine. The small 

 side fig. in fig. 52 illustrates the two valves at the anterior 

 end of the vena cava. 



The Lateral Venae Cavae, and the two vessels which 

 run into them from the venous sinus, bear the so-called 

 venous appendages on their posterior Avails (fig. 52, 

 AhJ.W and L.V.C.). These appendages are club-shaped 

 outgrowths of the vessel wall, arranged in live or six 

 irregular rows, the narrow end being that by which they 

 open into the veins. On opening up the lateral vena cava 

 (fig. 56) and examining the posterior internal wall, one 

 <ees the circular aperture leading info each venous 

 appendage. This aperture opens into a short vessel whose 

 walls are again pierced by other smaller apertures leading 

 into a smaller series of vessels similarly pierced, and so 

 on, so that each appendage contains in its interior a 

 system of radiating vessels which ultimately opens into 



