THE PROTOPLASMIC SYSTEM 



Opalina. Also among the higher animals certain sheets of 

 protoplasm as the binding or sustaining (connective) 

 tissue or the heart muscles of vertebrates show Innumerable 

 nuclei throughout their extent without Interposed cell- 

 boundaries. Such multi-nuclear protoplasmic systems are 

 called syncytia. 



The existence of syncytial protoplasmic systems has 

 given rise to theories opposed to the so-called cell-theory 

 which postulates that the cell Is the unit of structure and of 

 function. Rohde's vlews^ concerning the preeminence of 

 syncytia may be dismissed because they have little founda- 

 tion In fact. Similarly, Studnicka's arguments- as to the 

 living nature of cellular formations, fibres, etc., which 

 come to be extra-cellular, do not warrant discussion here. 

 The argument set up by Whitman^ and by Sedgwick,'^ 

 that the cell-theory of development is inadequate, out of 

 which have grown the so-called organlsmal and organlsm- 

 as-a-whole conceptions merits more attention although It 

 too has slight basis In fact and Is Indeed almost wholly 

 academic. 



These conceptions originated as protests against the 

 extremist's point of view that the individual cell Is the 

 end-all and be-all of life even In complex organisms; that 

 through exact knowledge of single cells one could win an 

 explanation of the organism as a unit. To-day we appre- 

 ciate the fact that a mere agglomerate of cells equal In 

 number to those that constitute an organism is not an 

 organism. That organisms are units and act as such, be 

 they composed of single cells, as Protozoa, or of myriads 

 of cells, as the higher animals, no one will deny. The 

 organlsmal or organlsm-as-a-whole conceptions have ren- 



^ Rohde, 192J. 

 '' Studnicka, ^934- 

 ^ Whitman, iSgj. 

 ^ Sedgzvick, i8q2. 



33 



