352 THE NATURAL IITSTOUT EETIEW. 



two books illustrate the two different modes of treatment of the 

 subject to w^hich we adverted in the notice of the " Handbuch der 

 Zoologie ;" and perhaps the extent to which Professor Bronn's work 

 threatens to attain, may serve to indicate the fact that the accumula- 

 tion of observations on the structure, habits and general classification 

 of animals, is now so great as to require a book of no small compass 

 for their satisfactory exposition. 



Some notion of Professor Bronn's idea of the nature of a treatise 

 on Zoology, may be gathered from his definition of the science and of 

 its various branches. " The task of Zoology," he says, "is to observe, 

 describe and arrange all animals in accordance with all their parts, 

 peculiar activities and extei^nal relations, and to arrange them in 

 such a manner that not only are the species brought together in pro- 

 portion to their mutual agreements in genera, families, orders, classes, 

 &c., but that these also are placed one above the other in accordance 

 with their degree of perfection. It consequently divides itself 

 into many separate branches, amongst which we may indicate as the 

 most important. Zootomy, or the dissection of all the formative parts 

 of the body ; Zoochemistry, or their chemical investigation ; Zoophy- 

 siology, or the science of the functions of the organs ; the tracing of 

 the changes of form, and of the course both of corporeal and intel- 

 lectual life from the first germ of the individual through all its ages 

 to its death, — and lastly, with regard to species and groups of species, 

 (a) their complete description or Zoography ; (b) their systematic 

 arrangement or Taxonomy ; (c) their geographico-topographical dis- 

 tribution ; (d) their geological evolution ; and lastly, (e) their 

 position in the oeconomy of nature." 



This being, as it were, the outline which Professor Bronn set before 

 him at starting, and which he conscientiously endeavoured to fill up, 

 it will be readily understood that his work takes far higher ground 

 than auy other treatise on Zoology, — aiming indeed at bringing 

 together the whole body of scientific Zoology, with the exception of 

 specific descriptions, which from the nature of the case could not be 

 included in his design. But besides all this he gives a prominent 

 place to the history of the science, indicating in his general introduc- 

 tion the chief observers by whose labours Zoology has been brought 

 to its present position, and detailing under each class, the different 

 views which have been entertained by naturalists as to the nature and 

 relationships of the animals composing it. The importance of a 

 knowledge of the history of a science to those engaged in its cultiva- 



