392 KARM NARAYAN BAHL 
fact is that the dorsal vessel is wholly ‘ venous’ behind the 
‘hearts ’ and wholly ‘ arterial’ in the region of the ‘ hearts ’ 
and in front (the whole of the cephalized region). The examina- 
tion of valves and experiments by cutting and pinching the 
blood-vessels in Pheretima confirm the results of Johnstone 
for Lumbricus as regards the course of blood in dorso- 
intestinals and commissurals and make Bourne’s theory unten- 
able. The ventral vessel is the arterial trunk throughout, 
while the venous function of the dorsal and subneural behind 
is taken up by the lateral oesophageals in the cephalized region. 
The thin-walled and non-contractile ‘loops’ of the tenth and 
eleventh segments must be distinguished from the thick 
walled and contractile ‘hearts’ of the other cephalized seg- 
ments, the ‘loops’ being the channels for conveying blood 
from the lateral oesophageals to the supra-intestinals. 
List oF REFERENCES. 
1. Bourne, A. G.—“‘On Megascolex coeruleus and a Theory of 
the Course of the Blood in Earthworms”’, ‘ Quart. Journ. Micro. 
Sci.’, vol. 32, 1891. 
. —— “On Moniligaster grandis”, ibid., vol. 36, 1894. 
3. Beddard, F. E.—‘‘ On the Structure of a New Genus of Oligochaeta, 
and on the Presence of Anal Nephridia in Acanthodrilus ”’, ibid., 
vol. 31, 1890. 
. —— ‘A Monograph of the Oligochaeta’. Oxford, 1895. 
5. Benham, W.—‘‘ Studies on Earthworms”’, ‘Quart. Journ. Micro. Sci.’, 
vol, 26, 1886. 
6. —-— “The Nephridium of Lumbricus and its Blood-supply”’, 
ibid., vol. 36, 1891. 
7. Bahl, K. N.—‘‘ On a New Type of Nephridia in Indian Earthworms 
of the genus Pheretima”’, * Quart. Journ. Micro. Sci.’, vol. 64, 
1919. 
8. Harrington, N. R.—‘‘ The Calciferous Glands of Earthworms, with an 
Appendix on Circulation’’, “Journ. of Morphology ’, vol. 5, Supple- 
ment, 1899. 
9. Jaquet.—‘‘ Recherches sur le systéme vasculaire des Annélides ”’, 
*Mitth. Zool. Stat. Neap.’, Bd. VI, 1885-6. 
10. Johnstone, J. B., and Johnson, Sarah W.—* The Course of Blood-flow 
in Lumbricus’”, ‘ American Naturalist’, vol. 36, 1902. 
11. Johnstone, J. B.—*‘ On the Blood-vessels, their Valves, and the Course 
of the Blood in Lumbricus’”’, * Biological Bulletin ’, vol. 5, 1903. 
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