CHAPTER XII THE EXCRETORY SYSTEM

excretory system. Topography and relationship of the excretory and reproductive systems vary greatly within the class of bivalves. Certain topographical features, however, remain constant. One of them is the position of therenal opening in relation to thecere­ bro-visceralconnective. Lacaze-Duthiers (1855), one of the early students of ... ................
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