INDUCED MUTATIONS IN DROSOPHILA
This extract was created in the absence of an abstract.
Excerpt
1. The Quantities and Qualities of the Expressed Effects
To date, radiation has stood as the only external agent by the artificial application of which mutations can be produced in abundance and with predictable frequency. The inordinate effectiveness of X-rays and related radiation in this respect has hardly been realized to the full. For when we say that a dose of 10,000 r-units results in about 100 times as many lethals per X-chromosome in Drosophila spermatozoa as ordinarily occur in untreated material, we do not take into consideration the fact that, in most such experiments, all these mutations were produced by a treatment lasting an hour or less, whereas the “natural” mutations represent the accumulation of a whole Drosophila generation, that is, of two weeks or more. When this time difference is taken into the reckoning, we find that, during the time of treatment here in question, not 100 times...
Footnotes
- 1
↵1 This is not intended to be more than a fragmentary list of literature on induced mutations in Drosophila and related matters, citing some of the main works dealing with points given special attention in the above paper. For lists of literature that aim to be more nearly complete on this of literature on induced mutations in Drosophila and on resubject, see Muller, 1928, 1930a and 1934a, Hanson, 1933, Oliver, 1934, and Timoféeff-Ressovsky, 1931, 1934a and 1937.
