CLASSIFICATION OF THE ANIMAL KINGDOM. ' 49 



Structure of the Animal Kingdom," by Professor Rymer Jones. Treating 

 of matter of the deepest import, it is written in language so plain and 

 simple, that the most superficial reader can at once grasp its contents; 

 and so interesting does each recital appear under the hands of this popular 

 writer, that it is with feelings almost of reluctance that we finish the 

 perusal of the book. In the course of the work, following out the systems 

 of C'uvier, Owen, and Mc'Leay, the author has classified the entire animal 

 kingdom by the distribution of the nerves, which, as he says, "must be 

 regarded as the very essence or being of all creatures, with which their 

 sensation, volition, and capability of action are inseparably connected;" and 

 no one who has perused the book can deny the completeness of the 

 arrangement; though, as will presently appear, it is impossible to carry 

 out the favourite scheme of so many, that of the gradual and regular 

 development of organic created matter, from one class of animals to another, 

 by a series of connecting links, each order and genus being in every res- 

 pect superior to the one immediately preceding; for in many places it 

 will be found that though certain families are undoubtedly superior in one 

 or more types of organization to those below them, yet in other respects 

 they are not so highly developed. 



Again, in refutation of the errors of such systematic naturalists, it will 

 be seen on perusing the Professor's book, that a particular series of 

 developments, which may perhaps run through several genera, is again 

 repeated in a still higher tribe, as, for instance, the gradual concentration 

 of the nerves, from Annelidans to the class Insecta, which is again repro- 

 duced, and, as it were, imitated in particular species of the single class 

 Crustacea, and so on. How far however the gradual superiority of one class 

 over another, in organic structure from the lowest to the highest orders, is 

 exemplified by the work before us, I will endeavour cursorily to shew. 



The first great division of the animal kingdom is called Acrita, or animals 

 whose nerves cannot be discerned, including, Sponges, Polyps, Polygastrica, 

 Acalepha, and Sterelmintha. 



The first and lowest — the Sponges — are animals composed of horny 

 elastic fibres of great delicacy, united with each other in every possible 

 direction, so as to form innumerable canals, which traverse its substance 

 in all directions. When alive, these simple animals are covered over in 

 every part with a coating of gelatine, the common sponge being in fact 

 only a skeleton of the origins*. They are invariably fixed, when alive, to 

 some rock or marine substance, and have not the slightest power of motion, 

 except when young. Their means of growth is by the continual suction 

 of the surrounding water through the smaller orifices, which is again 

 continually cast out from the large canals. They are reproduced by 

 mechanical division, and the growth ef little gelatinous gemmules, which on 



