118 



ANIMAL. 



III. Sub-regnum Cyclo-gangliatavel Mollusca. 



Classis 14. Tunicata. 



15. Conchifera. 



16. Gasteropoda. 



17. Pteropoda. 



18. Cephalopoda. 



IV. Sub-regnum Spini-cerebratavelVertebrata. 



Classis 19. Pisces. 



20. Amphibia. 



21. Reptilia. 



22. Aves. 



23. Mammalia. 



For the BIBLIOGRAPHY of this article see that 

 appended to each of the articles on the classes of 

 animals and COMPARATIVE ANATOMY (Introduc- 

 tion. ) 



( R. E. Grant.) 



ANIMAL (from anima, breath, the living 

 principle. Lat. animal. Gr. Qov. Fr. animal. 

 Germ. Thier. Ital animale). The objects of 

 the material universe were long considered as 

 arranging themselves naturally into three grand 

 divisions, or kingdoms, as they were called : the 

 animal, the vegetable, and the mineral. Closer 

 attention, however, and a more careful study of 

 the qualities and actions of the various bodies 

 composing these kingdoms, lead to the con- 

 clusion that two of them have much in com- 

 mon, and consequently that a two-fold division 

 suffices to comprehend the whole of the objects 

 in nature, these are the inorganic, or lifeless, 

 and the organic, or living ; the first embracing 

 minerals, fluids, gases, or the various forms 

 in which simple brute matter presents itself to 

 our observation ; the second including vegeta- 

 bles and animals. 



As the subject ANIMAL may be regarded in 

 the light of the very kernel and epitome of the 

 entire matter treated in the pages of our 

 Cyclopaedia, we shall give such extension to 

 this head as its importance seems to demand, 

 studying brevity nevertheless, and embracing 

 in general views the particular points which 

 will be illustrated in detail in the different 

 articles on anatomy and physiology, human 

 and comparative. 



COMPARISON OF THE ORGANIC AND INORGANIC 

 WORLDS. 



Physical qualities and elementary composi- 

 tion of unorganized and organized bodies. 

 The organic and inorganic kingdoms of nature 

 are distinguished from one another by many 

 strong features of difference, first, in reference 

 to their general physical qualities, external 

 form, volume, and elementary composition ; 

 and second, in regard to their capacities of 

 action. 



The forms of the objects composing the 

 inorganic world, indeterminate when they are 

 considered in their masses, are reducible to a 

 very few simple crystalline shapes when they 

 are regarded in their parts. The cube, the hexa- 

 hedron, the rhomb, the prism, &c. are the ele- 

 mentary forms of the inorganic world : plane 

 surfaces and straight lines uniting under differ- 

 ent inclinations, and originating angles that 

 measure certain determinate numbers of de- 



grees are the accidents, which give them their 

 characteristic and individual shapes. 



But the inorganic world has not absolutely 

 even this limited perfection of form, if the ex- 

 pression may be allowed. In order that the ob- 

 jects which compose it may exhibit themselves 

 under the form of crystals, solution of some 

 kind, rest, time, and space are required ; and 

 these or any of these being denied, the ob- 

 jects of the* unorganized world present them- 

 selves or exist as simple aggregates of mo- 

 lecules, shapeless in their component parts as 

 in their masses. And further, even when the 

 objects of the inorganic world do present them- 

 selves under definite forms, these are not ne- 

 cessary and invariable. Carbonate of lime, 

 to take a single instance, occurs crystallized 

 not only in rhombs, but in hexahedral prisms, 

 in dodecahedrons, the several faces of which 

 are pentagons, in solids terminated by twelve 

 triangles with unequal sides, &c. In their 

 material composition, too, unorganized bodies 

 are essentially homogeneous: one part of a 

 mineral does not differ from another. 



This is very different from what occurs in 

 the world of organization. From the lowest 

 to the highest of living beings the shape is 

 determinate for the individual, not only as 

 a whole, but even as each of its component 

 parts is concerned. Instead of being cir- 

 cumscribed within angles and right lines like 

 the objects of the inorganic kingdom, those 

 of the organic are mostly rounded in their 

 forms, or they are branched, or articulated and 

 made up of several parts, which present varieties 

 of conformation in harmony with the kinds of 

 offices they have to perform, or the conditions 

 surrounded by which the beings thus fashioned 

 exist. Neither do they consist of homogeneous 

 particles like minerals, but are made up in 

 general of heterogeneous parts : in plants we 

 have roots, leaves, branches, flowers, &c. ; in 

 animals muscles, nerves, bones, and a great 

 number of organs besides, each itself reducible 

 to a variety of simpler parts or elements, en- 

 titled tissues. 



The organic world also presents an immea- 

 surably greater variety of forms than the in- 

 organic : the myriads of animals and vegeta- 

 bles that people and possess the earth differ to 

 infinity from each other in their forms and 

 physiognomies. 



Size. Neither is there less discrepancy be- 

 tween the inorganic and the organic world in 

 the quality of size, which, in the first, is 

 perfectly indeterminate, being greater or less, 

 simply as the constituent molecules happen 

 to be aggregated in larger or in smaller num- 

 bers. The volume of organized bodies, on 

 the contrary, is determinate; every animal, 

 every vegetable, has a particular stature, a cer- 

 tain bulk, which is that of its species also, and 

 is within narrow limits alike in regard to all 

 the individuals composing the kind. 



Composition. Contrasted in their chemical 

 nature, organized and unorganized bodies pre- 

 sent numerous and striking points of dis- 

 similarity. Modern chemistry enumerates no 

 fewer than fifty-two elementary or simple sub- 



