THE BIOLOGY OF THE CELL SURFACE 



dered some service therefore in emphasizing this fact so 

 universally accepted. Enough is known concerning the 

 diiTerence in behavior between cells when en rapport with 

 others that make up the intact organism and those having 

 been isolated thereform, concerning the development of 

 eggs and the significance of the orderly sequence in time 

 and in space when specific embryonic cells are set off and 

 concerning the pathological growths, as tumors, to warrant 

 the clear conclusion that cells alone and as members of a 

 unit-system exhibit different behaviors. However, no suffi- 

 cient reason exists for assigning to cellular differentiation, 

 the integration of cell with cell, or the specificity of organ- 

 isms which resides only in cells and their products — all well 

 accepted biological truisms — the new terms of organismal 

 or organism-as-a-whole.^ Moreover, the principle of unity 

 — the expression of integration, differentiation and of 

 specificity both in form and behavior — which distinguishes 

 an organism from a mere mass of like cells, ought not be 

 elevated to the position of an abstract principle divorced 

 from the concrete physical basis on which living things are 

 organized. - 



An organism possessing no formed nucleus represents 

 one, and a mass of cytoplasm containing many nuclei 

 represents the other extreme type of protoplasmic systems. 

 If we assume that nuclear structure (and therefore from 

 it the discrete nucleus) is a derivative of the ground- 

 substance, the various types of protoplasmic systems can 

 be reconciled: the single nucleus of a simple cell is then 

 the compounding of nuclear bodies evident in non-nuclear 



^ I71 view of the claims of priority pressed by several writers 

 it may he worth-while to note that Descartes {1662) conceived 

 the organism as a whole. See Delage^s {i8g^) discussion of 

 " organicisme.'' 



2 See Woodger, i<p2g, 1930 and igii^for recent discussion of the 

 organism-as-a-whole point of view. 



34 



