ACKNOWLEDGEMENTS The author wishes to express his gratitude to the members of his doctoral committee for their advice, guidance and assistance in the preparation of this dissertation. Special acknowledgements of thanks are given to the author's major professor and advisor, Dr. J. F. Preston, for providing the laboratory facilities and supplies for conducting the research reported here. The laboratory techniques learned in his labora tory have already proved to be rewarding for the author in his pursuit of other research projects. The use of Euglena gracilis as a test organism for studying organelle development originated with Dr. Preston. He con tributed much of his normal off duty time offering advice and suggestions toward the completion of this study. The author also thanks Dr. R. F. Mans for the personal interest he took in the author's research and academic development. The advice and guidance he provided proved to be valuable in pursuing the study of nucleotide incorporations. The consultations held with Dr. Mans provided the stimulation to complete this research rather than to terminate it. In addition the knowledge obtained in the "Rusty Mans Molecular Journal Club" was most rewarding in terms of the author's academic development. Expressions of gratitude are also in line for Dr. L. 0. Engram for his encouragements when things looked bad and for his valuable suggestions that led to the completion of this research. Dr. Engram provided chemicals and laboratory facilities for conducting several experiments. iii