FUNCTIONAL HARMONY 33 



substances forming the first degree of composition are 

 principally C, N, H, O, and P, combined to form albumen, 

 fibrine, and the like, which are in their turn combined to 

 form the solids and fluids of the body. To the latter 

 circumstance Cuvier owes the statement that the finest 

 fragments into which mechanical division can resolve the 



o 



organism are little flakes and filaments, which, joined up 

 loosely together, form a <( cellulosity." The discovery of the 

 true cellular nature of animal tissues did not come till much 

 later, till some years after Cuvier's death in 1832. Knowledge 

 of histological detail was, however, considerable by the 

 beginning of the iQth century. Cuvier knew, for example, 

 that each muscle fibre has its own nerve fibre. But he gives 

 no elaborate account of the homogeneous parts, no detailed 

 histology. On the other hand his treatment of the hetero- 

 geneous parts or organs is detailed and masterly. 1 



The main systems of organs are, in order of importance, 

 the nervous and muscular, the digestive, the circulatory, and 

 the respiratory. Each organ or system of organs may have 

 many forms. If any form of any organ could exist in 

 combination with any form of all the others there would be 

 an enormous number of combinations theoretically possible. 

 But these combinations do not all exist in Nature, for organs 

 are not merely assembled (rapprockts), but act upon one 

 another, and act all together for a common end. Accordingly 

 only the combinations that fulfil these conditions exist in 

 Nature. Cuvier thus dismisses the question of a science of 

 possible organic forms and considers only the forms or 

 combinations actually existing. This question of the 

 possibility of a" theoretical " morphology "of living things, 

 after the fashion of the morphology of crystals with their 

 sixteen possible types, was raised in later years by K. G. 

 Carus, Bronn, and Haeckel. 



Organisms, then, are harmonious combinations of organs, 

 and the harmony is primarily a harmony of functions. Every 

 function depends upon every other, and all are necessary. 

 The harmony of organs and their mutual dependence 

 are the results of the interdependence of function. This 

 thought, the recognition of the functional unity of the 

 1 Lecons (f Anatomic Comparce, tome i., Articles iii.-iv., 1800. 



