422 
GENETICS: C. W. METZ 
Proc. N. a. S. 
bottles were kept, so the point cannot be definitely settled; but in any 
event the present degree of sterility in glazed stock suggests an inter- 
pretation of the sterility of the hybrids which differs considerably from 
that advanced previously. This is emphasized even more by the be- 
havior of the third character, wax, as will appear below. 
The three (allelomorphic?)^ mutants, rugose, glazed and wax, form a 
graded series in respect to their morphological characteristics and also in 
respect to fertility, but contrary to expectation the order of dominance 
of the somatic manifestations appears to be just the reverse of that of 
fertility. These features may be brought out more clearly by a brief 
summary of the salient points. I am indebted to Dr. Alexander Wein- 
stein and Miss Eleanor D. Mason for obtaining many of the records in- 
volved here. 
1. Rugose; characterized somatically by a slight paling and a roughening 
of the eye, evident only in the male, the female being entirely normal in 
appearance; in fertility both sexes seem to be fully equal to the wild type 
stock, as determined by a large number of matings and by the behavior 
of the pure stock cultures. 
2. Glazed; more extreme in all respects; the eyes have a glazed ap- 
pearance in both sexes, although the males are more noticeably affected; 
as noted above the females are usually sterile; among approximately 
150 females tested^ 3 were fertile, giving respectively 6, 7 and 8 offspring;^ 
apparently the males are also affected somewhat, for they do not breed 
as well as do rugose males. 
3. Wax; still more extreme; the eyes of both sexes are greatly affected, 
resembling masses of yellow wax; the females seem to be practically or 
entirely sterile; among approximately 100 tested no certain case of fertility 
was found. One bottle gave a single normal female, another gave a normal 
female and wax male. The first case is probably due to contamination, 
and the latter may be accounted for in the same way, although the 
presence of the wax male adds to the probability of actual, but very low, 
fertility here. The males, in turn, appear to breed more poorly than do 
the glazed males. ^ 
4. Hybrid females^ from rugose X glazed; somatic appearance normal as 
in rugose females; many tested, all sterile. (See Metz and Bridges, loc. 
cit.) 
5. Hybrid females from rugose X wax; somatic appearance normal as in 
rugose females; approximately 100 tested, one fertile, giving 19 normal 
females, 8 rugose males and 5 wax males. 
6. Hybrids of rugose, glazed or wax with any other mutants thus far 
used are all fertile. 
Reviewing these results it is seen that in each hybrid involving rugose 
and either glazed or wax, rugose is dominant as regards somatic manifesta- 
tion. But the sterility of the hybrids seems to indicate that the fertility 
