The common frog . Fig. 37.—Upper Surface of the Skull of a Froj (after Parker), e, os en ceinture, orgirdle-bone ; eo, exoccipital \ f, frontal part ot frontoparietal bone; inx, maxillary-bone ; «, nasal ; o/>, opisthotic ; /, parietal part of fronto-parietal bone ; pm, pre-maxilla; po, pro-otic: pt, pterygoid; q, quadrato-jugal; sq, squamosal; sus,suspensorium of lower Fic. 38. —Under Surface of the Skull of a Frog (after Parker), e, girdle-bone;eo, exoccipital : vtx, maxilla ; par, parasphenoid : /w, pre-maxilla ; po. pro-otic ;/;, pterygoid ; q, quadrato-jugal ; sus, suspensorium o
The common frog . Fig. 37.—Upper Surface of the Skull of a Froj (after Parker), e, os en ceinture, orgirdle-bone ; eo, exoccipital \ f, frontal part ot frontoparietal bone; inx, maxillary-bone ; «, nasal ; o/>, opisthotic ; /, parietal part of fronto-parietal bone ; pm, pre-maxilla; po, pro-otic: pt, pterygoid; q, quadrato-jugal; sq, squamosal; sus,suspensorium of lower Fic. 38. —Under Surface of the Skull of a Frog (after Parker), e, girdle-bone;eo, exoccipital : vtx, maxilla ; par, parasphenoid : /w, pre-maxilla ; po. pro-otic ;/;, pterygoid ; q, quadrato-jugal ; sus, suspensorium of lower jaw, the lower endof which represents the quadrate bone ; v, vomer ; 1, optic foramen ; 2, foramenovale ; 3, condyloid foramen. preserved this peculiarity of structure which all theirother class fellows have lost. It seems much more 76 THE COMMON FROG. [chap. probable that this structure has independentlyappeared through the action of peculiar conditions,and hence that we have here again a remarkableinstance of the independent origin of similarstructures. The third peculiarity of the frogs skull consists inthe form and conditions of the bony supports of the tongue. It would not be easy to find a better example ofthe need of widely extended observations in orderduly to understand structures apparently very simpleindeed. The bone of the tongue in man—the os Jiy
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Keywords: ., bookcentury1800, bookdecade1870, bookpublisherlondo, bookyear1874
