SEX-REVERSAL IN PARABIOTIC TWINS. 



141 



From the fact, that the reverse combination of a female with 

 a sex-changing co-twin was never found, it becomes evident, 

 that the male sex dominates the female one. 



FIG. 3. Same pair 8844. Right larva, same length as left one. Female. 

 Transverse section through one of the ovaries. The germ cells (primary oogonia 

 and auxocytes) are in the peripheral germinal epithelium, og., primary oogonia. 

 X444- 



