Organisms Covsistijuj of One Cell 229 



on all this he will sec a vast difference of meaning in the 

 word cell when used in the two assertions: "this object un- 

 der the microscope is a cell," and such generalizations as 

 "the key to all ultimate biological problems must be sought 

 in the cell." In the first case the term performs the com- 

 paratively simple office of a name for a particular object, 

 endowed, as one might say, with great ability to make in- 

 telligible certain phenomena of living beings. 



Undoubtedly the name stands for an idea in both cases, 

 and undoubtedly too, the ideas in the two cases must have 

 something in common, but equally certain is it that there 

 are important elements of difference in the two ideas. Of 

 the elements in common, one, we know very well, relates to 

 certain structural features, cytoplasm, nucleus, and so on, 

 experimentally settled upon as essential to any object en- 

 titled to be called a cell. Another is the conception that all 

 bodies so entitled arc a kind of organism, i.e., elementary 

 organism, this conception being based on the observation 

 that great numbers of cells are, in the language of O. Hert- 

 wig, "endowed with the attributes of life." Now notice: 

 by virtue of what is the cell conceived to be the key to all 

 biological problems.'^ Surely not in the mere presence in it 

 of bodies that may be called nucleus, cytoplasm, and so 

 forth, but rather because it is endowed with the attributes 

 of life, is an organism, even though of an elementary char- 

 acter. In other words, since typical cells are universally 

 admitted to be very simple in structure as contrasted with 

 those bodies to which the term organism was first applied, 

 and since it is now only one among such bodies, and that an 

 elementary and simple one, to assert that it is the "key to 

 all biological phenomena" is a logical contradiction, if by 

 being the "key" it is implied that the cell is an ultimate ex- 

 planation of such phenomena, for with such an implication 

 the assertion is virtually tliat part of a thing is greater than 

 the whole of it. 



