Xo. (Ul I 



TRANSFOEMATION OF SEX 



535 



is occupied by the shrinking ovarial sac with a degenerat- 

 ing egg. The spermatogonia are not numerous but they 

 are already dispersed throughout the wall of the ovarial 

 sac. The germinal ('])it1i('linin contains a degenerating 

 egg and an ovocyst. The third < ()i(l shows the beginning 

 of the process of trans) onnation. It is greatly enlarged, 

 but only a few spermatogonia have migrated into its 

 basal part. Numerous degenerating eggs are scattered 

 over the distal tissue of the sex cord. The germinal epi- 

 thelium is disintegrating. The second and the first sex 

 cords show tlic typical jn-oportions of an ovary: wide and 

 tliin-waUcd oxaria! >ac- and well-developed geraiinal 

 e|)itlie]iuni. The ovogonia adhere to the peritoneum, the 

 larger eggs projecting inwards. Thus the walls of the 

 sacs are folded on the outside. This preparation is taken 

 from a first year frog, several months after metomorpho- 

 sis. The transformation of sex in the grass frog often 

 occurs in the second vear but likewise is sometimes found 

 m adult animals. Eggs scattered through the testicular 

 tissue have l)epn fre(iuentlv ol)served, ])ut ignorance of 

 the ih^\ cloprncnt of tlic uonad lia^ ].i ()dn( cd the belief that 

 theN ucH duiNcd In. Ml .p. ii,ialoo,m,(^ IJm ctK I mv 

 and Suniulc < laini that IIicm ' ^...alKd ' . im^ ovW 

 ai( ( Ml iiii.d ..xo. Ml hk.' n al. -mn ..'1!^ and iimle 

 helie\.- tliat tli.« -...allMl MXiialK indilleieiit oi m'X- 

 uallv inlcniicdiatc loniis ..r the I 'tluiicr- llert wm" school 



.). loii^ ii|)eiiiPii a^ lai a^ llic j li^ t *'iie -tage " 

 (Ifi-J(M: aii.l "as a .'onscfiiien.-c ol this .-ii rla.ilment of 

 th<> iiiatui'ation .'n-cIc lo the carK' -tau'c- <il I he process. 

 NMth..iit .\. .ptioii iIm--. uiir.'i^ I Wit^. hi aii.l .)theis), 

 ])einminal.lcto<litl.i.Ptiat.Mt,aI, hoiii Iniiale .'oncluded 

 tliat all fn.u ta.l|H.i. ^ hi^t d. Nch.p .1^ I', iiiah ^ then later 

 liair or the reni;'lc ta.Ipolc- imi-1 traiistonn into 



