AIR VESSEL n.
A vessel, cell, duct, or tube containing or conducting air; as the air vessels of insects, birds, plants, etc.; the air vessel of a pump, engine, etc. For the latter, see Air chamber. The air vessels of insects are called tracheæ, of plants spiral vessels.
ALGA n.
A kind of seaweed; pl. the class of cellular cryptogamic plants which includes the black, red, and green seaweeds, as kelp, dulse, sea lettuce, also marine and fresh water confervæ, etc.
ALVEOLAR a.
Of, pertaining to, or resembling, alveoli or little cells, sacs, or sockets. Alveolar processes, the processes of the maxillary bones, containing the sockets of the teeth.