IQII] SHU LL 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. 



<f 



(Mutant) 



I I I 



Q 7* tt (Mutant) 



471 305 4 



FIG. 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 

 errors 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. 



