THE MUTATED GENE 9 



Further important facte have been added by other authors. 

 Jollos (1933) confirmed many of the foregoing findings in connec- 

 tion with work in a different line. Gottschewski (1034) found 

 that exposure to cold produced similar effects. This was to be 

 expected on the basis of the classic experiments on butterflies, 

 where Dorfmeister (1864, 1879), Merrifield (1889, 1894), Stand- 

 fuss (1896), and Fischer (1895) had shown that extremely low 

 temperatures produce the same modification- of the wing pattern 



Table 1. — Pkouiction of Dbfinitb Phenocopibb undbb Typical 



Conditions 



Phenotypr 



Scalloped 

 Curly .... 



Ski 



Spread . . . 

 Curved. . . 

 Dumpy . . 

 Lancet. . . 

 Miniature 

 Blistered . 

 Rolled 

 Trident. . 

 Eye size . . 

 Horns. . . . 

 Benign . . . 



Age days 



6-7 



ti ti'., 



5H 



5-7 



5 



7 



V., 7 



5-6 



7 



7 



51,-r, 



7 



35 



35-37 



36-37 



35 



36 



36 



36-37 



36-37 



36 



35-37 



35-37 



37 



35 



35 



Exposure, 



hours 



12-24 

 18 24 

 12 



18-24 

 18 

 12 

 18 



12-18 

 18 



18-24 

 C 24 

 18 

 24 

 18-24 



( >|if i 1 ■ 1 1 1 1 1 1 

 per cent of 

 phenocopies 



70 

 76 

 43 

 91 

 23 

 34 

 22 

 40 

 10 

 40 

 82 

 100 

 4 

 75 



as high-temperature shocks. In Gottschewski's freezing experi- 

 ments also phenocopies ni the eye-color mutants appeared, which 

 had been absent in the heat experiments. Recently Friesen 

 (1936) reported the production of phenocopies in Drosophila 

 by the action of X rays. His results, as far as they go, agree in 

 all the points mentioned with those of the temperature experi- 

 ments. It seems, however, that some of the phenocopies 

 produced by temperature shocks do not occur in the X-ray 

 experiments, and vice vcrsi. 



Here belongs also the report by Bobroff (1930) that X-ray 

 treatment of caterpillars results in males' showing some female 

 characteristics (see footnote, page 4). Geigy (1926) produced 



