PREFACE TO THE FIRST PART. IX 



according- to mode of action, partly according- to origin and 

 insertion, and partly according to position and form ; while in the 

 choice of new names I have given preference to the simplest. 



The figures are, with few exceptions, original, and drawn by 

 myself. Their careful execution in woodcut has added a very 

 necessary neatness to that correctness, which alone I claim as mine. 



ALEXANDER ECKER. 



ï'rbiburg, 



February, 1864. 



PREFACE TO THE SECOND PART. 



Sixteen years have elapsed since the first portion of this 

 anatomy of the frog appeared ; this second portion, therefore, 

 requires a somewhat apologetic introduction. 



The nervous and vascular systems have, in substance, been 

 known for some years ; still, certain points required a thorough 

 revision : this seemed especially necessary with regard to the cranial 

 nerves. In consequence of my anthropological investigations, and 

 particularly through undertaking the editorship of the 'Archiv fiir 

 Anthropologie,'' my attention was drawn into another channel, and 

 I found it impossible to work out this chapter : consequently the 

 whole was deferred, and would have been still longer delayed had I 

 not received assistance. 



At my request Professor Wiedersheim undertook to investigate 

 afresh the cranial nerves, the brain, the spinal cord, and the sympa- 

 thetic system ; and the descriptions of these parts are the result of 

 his work alone. I regard it as most advantageous to this second 

 part that so experienced an investigator in the anatomy of Amphibia 

 should have given me his help. 



The remaining portions appear almost unaltered as written 

 several years ago ; and the majority of the illustrations date from 



