Albino: a colorless individual of a species that is normally colored.
Albumen: the white of egg or the substances in the tissues which have the same characteristics.
Albumin: the characteristic substance forming the white of egg.
Albuminoid: like or of the character of albumen.
Alimentary canal: the digestive tract as a whole; begins at the mouth and extends through the body to the anus.
Alitrunk: that part of the thorax to which the wings are attached: in many Hymenoptera, includes the 1st abdominal segment.
Alizarine: a transparent, orange red [alizar crimson].
Alleghanian faunal area: is that part of the transition zone comprising the greater part of New England, s. e. Ontario, New York, Pennsylvania, Michigan, Wisconsin, Minnesota, eastern N. Dakota, n. e. S. Dakota, and the Alleghanies from Pennsylvania to Georgia.
Alligate -us: fastened or suspended by a thread; like the chrysalis of Papilio, etc.
Alliogenesis: when the development includes an alternation of generations (q.v.), as in Cynipids.