Chemically Induced Mutations in Neurospora

Before presenting the experimental data to be discussed in this paper we would like to emphasize some of the more general problems involved in the work on chemical mutagenesis. 1. It should be emphasized that the mutation concept of genetics is a very ample one, covering heritable changes, which we believe are due to changes in the individual genes (gene- or point- mutations) as well as changes which we know are due to various types of chromosomal changes. We have to accept this ample concept for historical as well as for methodological reasons. We accept it on historical grounds since some of de Vries's Oenothera mutants have later been shown to be due to true gene mutations, whereas others originated through various types of chromosome mutations. We accept it for methodological reasons since in most cases it is impossible—even in material as favorable as the salivary chromosomes of...