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 für 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 sympathetic 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 the same period. I had neither the time nor the zeal necessary to re-examine the whole; besides, it is doubtful whether eyes some twenty years older would improve matters.
This somewhat neglected book is therefore commended to the indulgence of my fellow-workers, with the hope that it may at least form a basis upon which further work may easily be done; to proffer more than this, as I stated, with a quotation from Sömmering, in the preface to the first part, I have never even hoped.
The final part of the work, on the viscera and sense-organs, has been undertaken by Professor Wiedersheim, and will appear in the Spring of 1882.
ALEXANDER ECKER.
Freiburg,
August, 1881.