RADIATION AND THE STUDY OF MUTATION IN ANIMALS 1245 



Table 25. — A Comparison of the Effects of Continuous and Interrupted 



Radiation in Drosophila melanoqaster 



Patterson (134) 



approximate 1. Muller (112) and Timofeeff-Ressovsky (185) have put 

 this to the test, with identical results. The temperature coefficient is 

 indeed 1, although curiously enough there is, in all three experiments, 

 a slight excess of mutations at the lower temperature (Table 26). This 

 may be an experimental accident, as Muller points out; its occurrence in 

 three separate experiments is none the less interesting, and may perhaps 



Table 26. — Temperature During Irradiation and Its Effect on the 

 Sex-linked Lethal-mutation Rate in Drosophila melanoqaster 



Muller (112); Timofeeff-Ressovsky (185) 



