396 RALPH S. LILLIE 



the stimulation-process in its various modifications (conduction, 

 inhibition, sensitization, anaesthesia, etc.)- The essential con- 

 ditions controlling intracellular processes are probably the same 

 in all cells; of these conditions surface-processes are now recog- 

 nized as all-essential; it is to be assumed therefore that they 

 determine many phenomena of cell-division, as of other cell- 

 activities. A somewhat more definite physico-chemical inter- 

 pretation of the above phenomena seems desirable as a work- 

 ing hypothesis; and the following conception of the conditions 

 within the dividing cell, partly a resume and sjaithesis of the 

 foregoing, seems consistent with the most general facts dis- 

 closed by cytological studies. 



Apparently there exist in dividing cells certain localized 

 reserves of oxidizable material; this material corresponds to 

 the 'archiplasm' or 'kinetoplasm' of cytologists;^^ it appears 

 to be present not only during division (when its quantity seems 

 to increase), but in the interkinetic intervals also, although 

 then usually difficult to detect; at the periods preparatory to 

 division, when the assumed change of surface-polarization 

 begins, it undergoes chemical change, e.g., oxidation — very 

 much as do the carbohydrate reserves in muscle-cells — with 

 the production of a diffusible electrolyte, e.g., acid; this, by 

 its diffusion into the surrounding cytoplasm, creates about 

 the active region ( = centrosome) a local electrical field, carre- 

 sponding to the diffusion-field; colloidal particles in this field 

 become polarized, and Irequently fuse to form radiating strands 

 along the electrical lines of force. These local radiating areas, 

 once formed, influence other cell-processes, e.g., the move- 

 ments of formative or other materials; their influence on the 

 distribution of chromosomes is evident, especially in polyas- 



*^ Its chemical nature is uncertain, but there is evidence that it is derived from 

 the nucleus; some of this material appears frequently if not usually to be intro- 

 duced into the resting egg-cell by the spermatozoon in fertilization (as evidenced 

 by the sperm-aster, hence Boveri's hypothesis) ; but apparently most is fur- 

 nished by the egg, as indicated by the possibility of parthenogenetic develop- 

 ment. Various facts indicate that the centriole consists of readily oxidizable 

 (i.e., strongly reducing) material; cf. the interesting paper of Mathews: Amer. 

 Journ. Physiol., 1907, vol. 18, p. 102. 



