Note 20 — Chapter IV · SPECIAL PROOFS, TAKEN FROM THE GENERAL LAWS OF ANIMAL STRUCTURE, OR FROM COMPARISON IN THE TAXONOMIC SERIES. General Principles.
Reading edition
While all comparative anatomists agree that the lung is a diverticulum from the œsophagus, like the air-bladder of the gar-fish, some think that it is a different diverticulum, which is seen first in the dipnoi.