External gills usually contains muscle tissue, and may be moved by the animal as a free appendage, in order to stir up stagnant water. The stalk is lined by many thinly walled filaments (fimbriae), containing the majority of blood vessels used in gas exchange. Animals usually have one external gill originating on each gill arch (except the hyoid), which leads to there being three pairs of external gills in salamanders, and four in the gilled larvae of lungfish. External gills External gills are the gills of an animal, most typically an amphibian, that are exposed to the environment, rather than set inside
Pint varies, but usually contains 425 ml. In Canada, the "pint of beer" served in pubs and bars has long been considered a colloquial term for "a large glass of beer". Legally speaking, after 1873, it was defined as one British imperial pint of 20 imperial ounces. On the other hand, the United States continued to use a smaller 16 imperial ounce pint, while in French Canada after 1873 a "pinte de bière" was defined as a much larger 40 ounce quart of beer, so confusion arose to which was being used. Prior to 1961, bottled beer in Canada was served