WHAT IS AN ORGANISM? 163 



the individual attains its form, and to this end we must 

 analyze the characteristics of an organism. 



The Definition of an Organism. Organism may be defined 

 in two ways: we may point to a concrete example and say, 

 " That cat is an organism" and then takeaway all those char- 

 acteristics which are peculiar to the particular example, as its 

 hair, its limbs, its eyes, its teeth, in fact, all its special organs 

 and parts, and come down to a fully abstract definition of an 

 organism, of which the cat is a concrete example; or we 

 may take the philosophical definition, and with Kant define 

 the organism to be ' * that whose every part is at once the means 

 and end of all the rest" For our purposes it is better to 

 combine the two methods, and say, An organism is a living 

 being whose every part is at once the means and end of all the 

 rest ; for it should be insisted that, whatever its full meaning 

 may be, living is an essential quality of any organism that 

 either develops or evolves, and the idea of organism includes 

 the necessary relationship of the parts to each other and to the 

 whole. 



Living and Performance of Physiological Functions are Essen- 

 tial Parts of the Definition of an Organism. -- " Under one 

 aspect," says Huxley, " the result of the search after the 

 rationale of animal structure thus set apart is Teleology, or 

 the doctrine of adaptation to purpose ; under another aspect 

 it is Physiology." * 



Inversely, then, a dead animal is not an organism. It is 

 only a mass of organic matter which some organism has con- 

 structed. So much are we engaged in handling dead animals 

 and plants that we are apt to overlook this important distinc- 

 tion. Too often the modern naturalist conceives of the 

 organism as only an aggregate of matter having a definite 

 form and structure of parts, as a house might be defined as a 

 building made of mortar and bricks. 



A Zoological Specimen in the Museum as much a Vestige of 

 Organism as a Fossil. The animals we see in the zoological 

 museums and dissect in the laboratories are as much remains 

 or vestiges of organisms as are fossils ; growth and structure 



* Thomas Henry Huxley, " An Introduction to the study of Zoology illus- 

 trated by the Crayfish," p. 47, New York, 1884. 



