Kidney always so simple; in cartilaginous fish and some amphibians, there is also a shorter duct, similar to the amniote ureter, which drains the posterior (metanephric) parts of the kidney, and joins with the archinephric duct at the bladder or cloaca. Indeed, in many cartilaginous fish, the anterior portion of the kidney may degenerate or cease to function altogether in the adult. In the most primitive vertebrates, the hagfish and lampreys, the kidney is unusually simple: it consists of a row of nephrons, each emptying directly into the archinephric duct. Invertebrates may possess excretory organs that are sometimes referred to as
Bladder pipe word which in medieval Latin was frequently used also for the bagpipe. In the earliest illustrated forms of bladder pipe, such as the well-known example of the 13th century reproduced by Martin Gerbert from a manuscript at Sankt Blasien Abbey in the Black Forest, the bladder is unusually large, and the chanter (or melody pipe) has, instead of a bell, the carved head of an animal. At first the chanter was a straight conical tube terminating in a bell, as in the bagpipe. The later instruments have a pipe of larger calibre more or less curved and bent back as