AMPHIBIANS OF THE FAR PAST 



63 



apart then as now. Fig. 33 is a cut of the true labj- 

 rinthodont tooth ah-eadj noted. 



Fig. 32.— Trematosaiirus. (After Huxley.) 



In the Triassic age the frogs appear, and we won- 

 der what it was that made tlie amphibians lose their 

 wrinkled teeth, set in the bones of the jaw, and 

 allowed the reptile only to bring these on up to the 

 present time. 



Professor Huxley remarks that since amphibians 

 seem to possess characters which belong to each of 

 the groups of vertebrates known as ^.^ ^ [ ^^| 



Ganoids, shark-forms and luns:- /"^^^ 4l^ f ^ ■ V' tr'4 

 fishes ; and since these are 

 known to be well sepa- >^ -:. ^^-^j^t^\».;<''<'^l,i::|^.^^ 

 rated from each other y^ ->:«> )^-:-^'^^^^!'>:;^^^ 



kM^f- 



very far below the /;::;;% i.:;p^,^P^^ 

 place where any fos- ^'^"^^^^^^iv^^?^^ 

 sils of amphibians r'^-^-^-,r0\^'/))f^ 

 are found, it is f --^'^^■'''^•'^^fcirt/'^ii^^-'- 

 quite probable 



^-'^^^/r:y 





that these latter W'^^^^'^'r-lM,:^-^ 



branched from ^ " '' "•'^^" ' •^•^'^' '^^'"^ "" ^^^^^^^^' •^i" ^LLiij.^.^ 



■^ 



Fig. 33.— Section of tooth of a labyriiithodout. 



the parent back- 

 boned ancestor at about the same time that the others 

 did, and hence are very ancient. To the author it 



