126 REPORT — 1860. 



zoology, but moreover as the founder of the natural system and of the science of 

 comparative anatomy. 



As I intend to inquire into the value of one of the most striking characters of 

 animals with regard to their classification, as well as to their typical organization, 1 

 may be allowed to state, first, what is meant by a Systema Animalium, or in other 

 words, what place the classification of animals takes among the branches of zoolo- 

 gical inquiry. 



We are scarcely aware that we use the word system of animals in quite a differ- 

 ent sense from that in which Linnaeus used it, and which was intended even by Cuvier 

 when he arranged the animal kingdom anew according to its organization. Even 

 Cuvier compares the system to a great catalogue of animals, in which every single 

 one can easily be found and named. There is, however, one great feature stamped 

 upon all forms of organized beings, which, although implied and even indicated in 

 the system of Cuvier, yet has given to the system of animals quite another aspect, 

 — I mean the relationship between different animals. Cuvier, and some later natu- 

 ralists, and I may say some of the best, considered the system only as a servant to 

 true science. Classification, according to them, is nothing more than, as Stuart Mill 

 says, a contrivance for the best possible ordering of tbe ideas of objects in our minds, 

 and at most " for causing the ideas to accompany or succeed one another in such a 

 way as shall give us the greatest command over our knowledge already acquired." 

 Although a classification worked out in the most perfect manner in this way must 

 also be one of the aims of our endeavours, yet I may say that our present classifi- 

 catory inquiries go further. They start from the very fact that the oldest fonns, 

 and for this reason the forms nearest to the original creation, do not represent anv of 

 those groups of individuals which we are used to call species ; nor can all of theni be 

 classed under the now established genera, families, and orders, but only under the type 

 to which all succeeding species belong. And although we cannot give the direct "ex- 

 perimental proof, yet we are boundbylogicandbytruths forced upon us from all other 

 branches of natural history, to say that these oldest original forms are tbe primaeval 

 forms of all living animals, which originated from them by continued generation 

 and by accommodation to external circumstances continually and progressively 

 changing*. Hereby the general bearing of the system of animals is totally changed. 

 We consider it not only as an arrangement of the animals in such a manner as 

 may help us best in gaining a general view of the animal world, and in placing 

 and finding certain forms of it ; but we try to make it the faithful expression of 

 the state of our knowledge respecting the relation of all animals to each other. 



Passing from the much spoken of differences between artificial and natural 

 systems, I may only state, that even that arrangement, which is mainly founded on 

 the internal structure of animals, is nothing more than a somewhat modified form 

 of artificial system, taking only one set of properties as basis of the classification. 

 However, it is the best form hitherto proposed, because it takes into consideration 

 more characters than any other arrangement, and leads us naturally forward in the 

 study of animal life. There is as yet one great chasm which severs the classifi- 

 cation of minerals from that of animals. In the mineral world we are justified in 

 speaking of species, as the identity of physical and chemical properties grants us the 

 identity of all bodies endowed with these. In the animal world we have nothing 

 but individuals, and all sorts of groups are entirely and totally artificial. The law 

 of equal production of like from like through generations and generations, upon 

 which the notion of the species mainly is based, cannot be trusted to, as we have no 

 experience whatever that it holds good for the same animals under different circum- 

 stances. 



Passing in review the leading characters upon which the different subkingdoms 

 of the animal world are founded, we perceive at once that they change almost in 

 every class. For although the general headings may be taken from the same system 

 of organs, yet the splitting of the classes and orders into minor divisions is de- 

 pendent on characters especially modified by these very classes and orders. And 

 even here our classification is not quite consistent. Amongst the lower classes of 

 animals, the comparatively simpler organization allows us to take the general form 

 of the bodies as a character to be relied upon, yet no person would be able to call a 



* I first made the foregoing remarks in my ' System of Animal Morphology,' 1S53, 

 Introduction. 



