II. Studies in tunicate development. Part I.— General physiology development of simple Ascidians

Abstract

The development of Ascidians formed the subject of numerous investigations during the latter part of the last century. The interest, however, which was due primarily to the recognition of the chordate characters of the swimming larvae, and was almost entirely morphological in outlook, then diminished. The present paper is a study from a functional viewpoint and deals with the development typical of most simple ascidians. An account of the abbreviated development to be found within the family Molgulidae and the accelerated development typical of compound ascidians will be presented in later publications, together with the more general conclusions arising from the study of the class as a whole.