Student Theses and Dissertations


Lorna Green

Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)

RU Laboratory

Weiss Laboratory


Pigment granules in melanocytes of Fundulus heteroclitus exhibit both local movements and long distance intracellular migrations in response to hormones. These movements have been studied and a theory of the granule moving system has been proposed: The granules are in a structured continuum which expands and contracts to move them; the state of the continuum is the resultant of a dynamic equilibrium between expansile and contractile forces manifested in the local movements of granules. The fine structure of the cell has been explored by electron microscopy; the prominent features of the cell are microtubules. Several alternatives for the specific granule moving apparatus have been discussed. In the light of these studies, previous theories of the mechanism of granule movement have been ruled unlikely.


A thesis submitted to the Faculty of The Rockefeller Institute in partial fulfillment of the requirements for the degree of Doctor of Philosophy

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