Bibliographical Notices. 609 



fesses to treat of the comparative anatomy of animals, the question 

 of classification is one of secondary importance as far as he is con- 

 cerned ; but this plea can hardly be admitted, inasmuch as a com- 

 parative anatomy must of necessity take a zoological classification 

 for its foundation, and the nearer the truth we can bring this, the 

 better will be our representation of the "organization of the Animal 

 Kingdom." 



Notwithstanding the faults above referred to, Professor Rymer 

 Jones's work will be found to contain a most valuable outline of the 

 structure and development of the different classes of animals, al- 

 though it is to be regretted that, in the consideration of the latter 

 portion of the subject, his unfortunate views of classification again 

 step in, and certainly prevent his giving that importance to the earlier 

 stages of some groups which they deserve, if indeed they have 

 not induced him rather to throw them into the background, as 

 matters of comparatively little consequence. The same circum- 

 stance of course prevents the reader from finding any reference in 

 the pages of this book to the doctrine of a retrograde metamorphosis, 

 which not only applies to such groups as the Epizoa and Cirrhopoday 

 but is also adapted to throw much light upon the position in nature 

 of other anomalous animals, which have generally been puzzles to 

 zoologists. As a general rule, however, the information seems to 

 have been pretty carefully brought down to the present time, al- 

 though we notice several omissions of greater or less importance in 

 different parts of the work. One or two of these we may mention, 

 as we can hardly understand how Professor Rymer Jones could have 

 made them. Under the Cephalopodous Mollusca, we find not the 

 slightest reference to those curious spermatophora the Hectocotyli ; 

 and in his description of the bulbus arteriosus in Fishes, our author 

 states that it is of a muscular nature, although Professor Miiller 

 has shown that it is nothing of the kind in the ordinary fishes : and 

 in mentioning the existence of the numerous valves in the arterial 

 bulb of the Sharks, &c., he has taken not the least notice of the 

 occurrence of the same structure in the Ganoid Fishes, although it is 

 upon this character that the order Ganoidea now reposes. We can 

 hardly suppose that Professor Rymer Jones is in utter ignorance of 

 Miiller' s admirable paper upon the Ganoid Fishes, which has been 

 published about twelve years, and must attribute his omitting to take 

 any notice of it to its having in some way slipped from his memory. 



However, with all these omissions and an occasional misstatement of 

 minor importance, there can be no doubt that Professor Rymer Jones's 

 volume contains an immense amount of valuable information, well put 

 together, and adorned with all that elegance of language for which 

 the author is particularly distinguished. As in his previous edition, 

 he commences with the lowest forms of animals and proceeds from 

 these upwards in the scale of existence to the Vertebrata, a mode of 

 arrangement which certainly has many advantages. The numerous 

 woodcuts with which the work is profusely illustrated are of the 

 highest excellence and very well printed, whilst the general utiUty of 

 the book is greatly increased by the admirable double index, con- 



