VI PREFACE 



notion of the l)eauties of the swamp" — lirilliautlj coloured 

 Xewts engaged in amorous play, concert-giving Frogs, and meta- 

 morphosing Tadpoles. The motto assigned to the Eeptiles seems 

 singularly appropriate when we consider that poisonous snakes 

 ha\e l)een developed from harmless forms, and that many kinds 

 of reptiles have lost linilis, teeth, and eyesight in the process 

 of evolution. 



The present work is intended to appeal to two kinds of 

 readers — to the field-naturalist, who, wliile interested in life- 

 histories, habits, and geographical distribution, l^eauty or strange- 

 ness of forms, is indiflerent to the homologies of the metastemum 

 or similar questions ; — and to the morphologist, who in his turn 

 is liable to forget that his specimens were once alive. 



A great portion of the book is anatomical and systematic. 

 It was necessary to treat anatomy, especially that of the skeleton, 

 somewhat fully, since it has long Ijeen recognised that it is 

 im])ossil:)le to base a scientific classification upon external 

 characters. Tlie reader familiar with Yertel»rate anatomy has a 

 right to expect that questions of special morphological interest 

 will be dwelt upon at length. Tiiose who have no anatomical 

 foundation must be referred to one of the now numerous intro- 

 ductory manuals on the subject. 



The account of the Am]ihiliia is more complete than that of 

 the IfeptiUa. It was possible to diagnose practically all the 

 recent genera ; and this has been especially done in the Anura, 

 in order to sliow how in au otherwise very homogeneous group 

 almost any part of tlic liody, internal or external, can be moditicd 

 in kaleidoscopic variety. The same could not be done with the 

 Eei'tilia. Their principal groups, — called sub-classes in the 

 present work, in order to emphasise their taxonomic importance 

 in comparison with the main groups of IJirds and Mannnals, — 

 dilfer so much from each other that it was decided to refrain 



