Xo. 63S] TXTEnXAL S KCBKTJOXS OF AMPHIIUAXS 209 



species a- c-alciilntrd ri-ciii \\\v l.-n-.-t kiM.\Mi t .■i-i'.-l i-ial 

 speciiiieii^ of {he (.a^tci-ii race cf ilii- -pcci,.^: ihc r,,l,)- 

 rado axolotls arc .i^iaiits. Since sexually iiiatmv <\u-v\- 

 mens of the eastern race of A. Ininmnn l»cc<»iiic if 

 they are fed anterior lobe of liypophysis, ili,- uioaniiHii 

 of the sexually mature axoloti c.uld he cxplainc.l if ;iiiy 

 indications of li\pci-pituitai'isiii of tlc-c animal- could lie 

 discovered. On the a -sum pi ion that in spite of the pres- 

 ence of a laruv tlix roid the function of this (»r-an i- -up- 

 pressed by the absence of the releasing' factor, the oxer- 

 function of the axoloti liyj)oi)hysis would lie \ery 

 plausible, since, as will l)e i)ointed out later on. the al»- 

 sence of the tliyi-oid function causes hypertrophy of the 

 hypophysis in auiphihlati larvae 



incompatible witli the assumption of an athyroidisni, 

 since, as will be di>cu-M.d pr<'M.nll>. there can be no 

 long-er any dou1)t that the dexclopment of the sex oruans 

 of amphibians is entirely ind. ■pendent of the thyroid 



