PLATE 3 



Fig. 11. Ambystoma jeffersonianum $ x Triturus torosus (^ (jef-Ti.); cross 

 section through gonads at the age of 13 months, x 94. 



Fig. 12. Ambystoma tigyinimi (^ x Triturus torosus, undifferentiated (tig-Tg); 

 cross section tlirough gonads, x 188. 



L 674 -} 



