( 383 ) 



with the other species of epitheUum, taught us that there is, as is 

 the ease with bladder-epithelium, a regular connection between the 

 volume of the cells and the concentration of the salt-solution used. 

 There was. however, considerable difference in the amount of the 

 alterations of volume under the influence of salt-solutions in different 

 oesophagi of the same species of animal. 



On studying our notes, however, it was soon obvious that a slight 

 dilation or contraction was always accompanied by the presence of 

 many grains in the cell. 



And so the idea occurred to us that these grains were answerable 

 for the relatively slight changes in volume. 



"With this hypothesis in view, we made some comparative deter- 

 minations with oesophagus-epithelium and blood-corpuscles of the same 

 animal, and we found a striking correspondence between the mag- 

 nitude of the changes in volume of the two cells produced by the 

 same salt-solutions ; but only in the case that the microscope showed 

 a small cjuantity of grains in the epithelium. 



As an instance of this we communicate the following experiment : 



Experiment LII. 



Oesophagus-epithelium of a pig and defibrinated blood of the 

 same animal are mixed with Na Cl-solutions of 0.7o/(, and 1.5%, 

 and both pairs are simultaneously centrifugalized half an hour 

 afterwards. 



Volume 



of epithelium. 



Contraction of NaCl 

 of 1.5=/^ 



a. NaCl-sol. of 07°/o^ 



oesophagus- 

 epithelium. 



c. NaCl.sol. of 0.7»/,^ ^^^^,^^^. 



d. „ . ,1 1.5°, \ t^OfPuscles. 



82.5 

 59 



90 

 64.5 



2.5—59 



82.5 



■X100 = 88.8°/o 



90—64.5 



90 



X 100 = 88.3% 



The change of volume of the oesophagus-epithelium corresponds 

 in a striking manner to that of the blood- corpuscles. 



The experiments, then, have successively taught us that in tvhite 

 blood-corpuscles, spermatozoa and oesophagus-epithelium the proportion 

 of the volume of the protoplasmatic substance (including the chro- 

 matine-threads of the nucleus) to the volume of the intracellular 



