382 KARM NARAYAN BAHL 
for the course of blood in the dorso-tegumentaries, and | am 
convinced that his statement with regard to the primitive 
condition that I have quoted above holds for adult Phere- 
tima, and in fact all earthworms. Both by a study of 
the disposition of valves, and by cutting the commissurals 
and observing from which of the cut ends the blood flows, 
I am convinced that blood flows into the dorsal vessel from the 
commissural vessels as it does in the case of the dorso-intestinals. 
In fact I believe that the dorsal vessel all along the body of the 
worm behind the first thirteen cephalized segments is a channel 
only for collecting blood and propelling it forwards. It gives 
out no blood at all behind the thirteenth segment as it receives 
none in the first thirteen segments; so that we have two 
clearly marked divisions of the dorsal vessel—the large pos- 
terior division of it behind the ‘ hearts’ being the collecting 
channel, and the anterior short division of the first thirteen 
segments being the channel for distribution of all the blood 
collected behind. 
As regards the disposition of the valves situated at the 
entrance of the dorso-intestinals and the commissurals into 
the dorsal, they are easily seen in transverse sections projecting 
into the lumen of the dorsal vessel. In two lucky preparations 
of the dorsal vessel, in which the latter was torn open and fixed 
with the valves projecting out into the open lumen, I have 
been able to see the valves displayed in an admirable manner. 
They are shown in fig. 7. The valves are seen in two condi- 
tions, i.e. either protruding inwards into the lumen of the dorsal 
vessel or flush with the wall of the vessel. In the former 
condition they are more or less conical in shape, the blunt 
apex of the cone forming the projecting end into the dorsal 
vessel, and the base being continuous with the wall of the 
vessel; in the latter condition there is nothing projecting 
into the lumen of the dorsal vessel, and the valves look like 
closed sphincter muscles in the wall of the vessel, the actual 
valves being contained in the upper ends of the dorso-intestinals 
or commissurals. ‘There can be no doubt that these two 
conditions of the valves represent them as they are during the 
