NOTICES OF BOOKS. xix 



advanced with great rapidity. The work of Edinger and others on the 

 intestinal epithelium of fishes, of Bizzozero and his followers on that 

 of the tubular intestinal glands, the discovery of a true pancreas in the 

 bony-fishes, of pancreatic and splenic tissues in the dipnoi lying wholly 

 within the wall of the gut, and of the compound origin of the pancreas 

 in representative species of the several great groups of vertebrates, to- 

 gether with observations on the functional side no less welcome and 

 important, have brought harmony into confusion and simplified our 

 conceptions not a little, necessitating a stocktaking of the sum of our 

 knowledge in this generally interesting department. To Dr. Oppel has 

 fallen the task of meeting the latter demand, and the present volume 

 is the second of two which he has devoted to the purpose, the first 

 (on " The Stomach ") having preceded it by but a year. Contrary to what 

 might be expected, the work thus rapidly issued, is exhaustive, most 

 carefully executed, and thoroughly reliable, and there is evidence of its 

 having occupied its author's attention for several years. Its 664 pages 

 are amply illustrated by 343 well-chosen text-figures and four plates of 

 great excellence. A full bibliography and analytical indexes are given, 

 and the pages of the work are thoroughly salted with references. The 

 whole arrangement is a well-conceived one, whereby the reader is 

 without difficulty enabled to ascertain precisely what has been observed 

 concerning a given species, and where to turn for fuller information 

 upon details. The book is in fact the embodiment of our ideal of the 

 work of reference which we believe the advanced text-book in Science 

 of the future must become. The author has solved the problem of 

 compressing within reasonable limits and presenting in a thoroughly 

 workable form the sum of our knowledge of a vast subject, and that 

 more successfully than most with whose books we are familiar. We 

 note the omission of some few references and of topics which might 

 well have been considered, but all that is leading and important is 

 there. The compilation of works of this order has now become a 

 necessity if energy in the future is to be economised and directed into 

 the channel best conducive to advancement, and to those disposed to 

 enter upon the task of ensuring this, Dr. Oppel's book may well be 

 recommended as a pattern. 



The Tailless Batrachians of Europe. Part i. By E. A. Boulenger, 

 F.R.S. London : The Ray Society, 1897. 



This book, primarily intended for the English scientific public, deals 

 with a group of animals ever popular and conspicuously associated 

 with the work of English-speaking zoologists. Its 204 pages are 

 illustrated by seventy-seven processed drawings, and nine plates, of 

 which six are coloured, and by two maps ; and we have no hesitation 

 in stating that it is one of the most important additions to zoologi- 

 cal literature during recent years. It deals comprehensively in its 

 " Introduction " with the Amorous Batrachians, classified according to 

 Cope's system, which all recent investigation has gone to support, 

 and categorically in the eighty-eight pages which follow with the 

 Discoglossidce and Pelobatidce, the latter mode of treatment of the 



