XLIX. THE PARTIAL-FUNCTIONS OF CELLS.* 



By Prof. PAUL EHRLICH. 



THE history of our knowledge of vital phenomena and of the 

 organic world can be divided into two parts. For- a long time 

 anatomy, especially the anatomy of the human body, constituted 

 the beginning and the end of scientific knowledge. Further progress 

 was only made possible by the invention of the microscope. Many 

 years, however, passed by before Schwann demonstrated the cell 

 as the final biologic unit. It would be like carrying wisdom to 

 Athens to sketch for you the immeasurable progress which we owe 

 to the introduction of the cell concept, the concept about which the 

 entire modern science of life turns. 



I take it to be generally accepted that everything which goes on 

 within the body, assimilation and disassimilation, is referable, in 

 the final analysis, to the cell; that the cells of different organs are 

 differentiated from each other in a specific manner, and that this 

 differentiation makes it possible for them to fulfill their various 

 functions. 



The results mentioned were achieved principally by histological 

 examinations of dead and living tissues, though the allied sciences, 

 physiology, toxicology, and especially comparative anatomy and 

 biology, made most valuable contributions. Nevertheless I am 

 inclined to believe that the aid which the microscope has given and 

 can still give us is approaching a limit, and that in a deeper analysis 

 of the all-important problem of cell life the application of optical 

 contrivances, no matter how delicate, will fail us. The time has 

 come for a further study of the minute chemistry of cell life; the 

 concept cell must be resolved into a large number of distinct partial 



1 The Nobel Lecture, delivered in Stockholm, Dec. 11, 1908. Reprinted 

 from Miinchener mediz. Wochenschrift, No. 5, 1909. 



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