THE CELL AND PROTOPLASM 



By C. V. TAYLOR 



SCHOOL OF BIOLOGICAL SCIENCES, STANFORD UNIVERSITY, CALIF. 



The sixteen papers comprised in this 

 volume were presented in a Symposium on 

 The Cell and Protoplasm at Stanford Uni- 

 versity, June 30-July 5, 1939. The occa- 

 sion commemorated the one hundred years 

 of advancement in knowledge of the proto- 

 plasmic unit of living things after Schlei- 

 den and Schwann's formulation of the Cell 

 Theory. 



The participants were men of merited 

 eminence, including several distinguished 

 biologists whose names have been familiar 

 in biological science for more than a quar- 

 ter of a century, along with others whose 

 more recent analyses of the cell and its 

 constituents have greatly extended the con- 

 fines of biological knowledge and have 

 doubtless pointed the w^ay for further stud- 

 ies of fundamental importance. 



The first three papers have to do pri- 

 marily with early and modern concepts of 

 the cell and protoplasm. The initial article 

 by Professor Conklin on "An Historical 

 Account of Cell and Protoplasm Concepts" 

 reviews the results of investigations on the 

 cell previous to the work of Schleiden and 

 Schwann. The accurate descriptive ac- 

 counts of these earlier investigators have 

 evidently not been adequately recognized. 

 Thus the degree of credit commonly ac- 

 corded Schleiden and Schwann appears to 

 be unwarranted because their accounts 

 were antedated many years by the pub- 

 lished findings of various, even superior, 

 workers beginning notably with Robert 

 Hooke (1665). This well illustrates the 

 social nature of scientific discovery and 

 rightly emphasizes that the end results of 

 the successive achievements of many minds 

 may come to have rather exclusive, and so 

 undue, recognition. 



The second paper, by Professor Cham- 

 bers, on "The Micromanipulation of Liv- 

 ing Cells," helps to resolve our modern 



concepts of these living protoplasmic units 

 to the essential nature and properties of 

 their molecular constitution. As can be 

 strikingly illustrated by motion pictures, 

 the protein constituents of the protoplasm 

 tend to retain their inherent state in the 

 presence of an engulfed droplet of oil. 

 Upon cytolysis, however, as induced 

 through mechanical rupture of the nucleus 

 or otherwise, a protein "skin" forms and 

 becomes wrinkled around the droplet, much 

 as also happens when such a droplet is 

 added to a protein solution on a micro- 

 scope slide. This unique behavior of the 

 protein constituents of the protoplasm 

 would seem to indicate a coherent property 

 of proteins in the living cell which may be 

 irreversibly changed if the characteristic 

 structure of its protoplasm is disrupted. 



Another modern aspect of the cell and 

 protoplasm, gained chiefly from studies on 

 protoplasmic elaborations, is presented in 

 Professor Bailey's article on "The Walls 

 of Plant Cells." The structural pattern of 

 the cellulose wall laid down by the proto- 

 plast evidently should offer invaluable 

 clues to the nature and interaction of the 

 protoplasmic constituents. Thus, the regu- 

 larity of a specific pattern — whether con- 

 centric, radial, ramifying, or radiocentrie 

 — of a given cell wall would seem to reflect 

 a predisposed regularity in the arrange- 

 ments and orientations of constituents at 

 the interface where the cell wall is derived. 

 All evidence thus far indicates that the 

 cellulose matrix of the cell walls of higher 

 plants is a continuous, rather than a dis- 

 continuous, system of anastomosed chain- 

 molecules whose long axis is oriented par- 

 allel to the long axis of the cellulose fibril. 

 They exhibit positive anisotropy and 

 sharply defined extinction angles in mono- 

 chromatic polarized light. At present, 

 there is no reliable evidence that the struc- 



