Quarterly Journal of Microscopical Science, Vol s2-83, 423-457, Copyright © 1942 by Company of Biologists

Studies on the Structure, Development, and Physiology of the Nephridia of Oligochaeta

Part I. General Introduction, and the Nephridia of the Sub-family Octoehaetinae

¹ Department of Zoology, University of Lncknow, India

The nephridia of Thamnodrilus, Hoplochaetella, and Lampito are provided with multiple funnels. In Tham - nodrilus all (from 28 to 34 on one nephridium) are large and functional; in Hoplochaetella one is large and functional, while the other 18 to 24 are small and complete, but are arrested in development in that they have solid necks with no canals in them; finally, in Lampito, there is one functional funnel with one to three solid masses of embryonic cells representing mere vestiges of other funnels. The nephridia of these three genera, therefore, form a graded series showing multiple funnels, which are all complete and functional in one case, but show a progressive degeneration of all except one in the other two cases. Just as the body of the embryonic nephridial cord in Eutyphoeus proliferates to form several meronephridia, similarly in the three genera enumerated above the funnel-rudiment proliferates to form several funnels. In the expressive language of Stephenson (3), we might say that the funnels in these genera ‘have been caught in the act of dividing up’.