1911] SHULL—REVERSIBLE SEX-MUTANTS 341 
parent having had any hermaphrodite connections. It appears 
fair, therefore, to consider these four hermaphrodites simply 
as mutants, and not as genetic derivatives from their maternal 
grandfather. The few hermaphrodites occurring in the families in- 
cluded under the present case may be related to the fact, however, 
that the females belong to a hermaphrodite family, for the same 
male 0855(36) was crossed with seven other females and with one 
hermaphrodite, and among the 443 offspring produced there were 
no other hermaphrodites. 
= 2 
\—_ 
mm OXe 2 of 
rf 
Ee | 
| | | 
oe a 
471 305 4 
Fic. 5.—Model pedigree for case V 
Allowing for the same frequency of occurrence of hermaphrodites 
as shown in the table above, there should have appeared among 
these 443 individuals derived from the same male crossed with 
other females at least two hermaphrodite mutants. This number 
is so small that they may possibly have been omitted through the 
€rrors of random sampling, but the suggestion may be made that 
while a female cannot transmit hermaphroditism to its offspring, 
it may perhaps supply an intracellular environment favorable to 
the mutation of the male genes into hermaphrodite genes. 
