Action of the Rete Mirabile in the Secretion of Gases by Blood-acidification in the Swim-bladder of the Eel

SEVERAL theories have been advanced to explain how gases are secreted into the swim-bladder of fishes. Haldane 1 suggested that oxygen is dissociated from oxyhæmoglobin by acidification of the blood and then diffuses into the bladder. Ball et al. 2 , Hogben 3 , Fänge 4 and others presented evidence in favour of this; Scholander et al. 5 , however, investigating the effect of acidification of blood from deep sea fishes, concluded that the acidification theory in its present form cannot explain gas secretion in these species at great depth. Scholander et al. 6 later showed by experiments with oxygen-18 that all the oxygen which is secreted is derived from that dissolved in the water.