Abstract

It was thus the combination of observational and experimental approaches that ultimately led to confirmation of the outgrowth theory. The observational method was essential for defining various possible methods of nerve fiber development. The multicellular, protoplasmic bridge and outgrowth theories were each postulated to explain purely observational evidence. However, the lack of truly suitable equipment and techniques to study the developing nervous system made it impossible to agree on a single theory on this basis alone. The experimental method provided a means of choosing between these theories. Without the preceding observations that had led to the formulation of various hypotheses, however, the experimental approach might not have been so successful, for the power of this method is more of selection than of generation.Therefore it is impossible to weigh separately the contributions of the observational and experimental approaches to the question of nerve fiber development. Both were necessary for the ultimate acceptance of the outgrowth theory. *** DIRECT SUPPORT *** A8402051 00004