( 377 ) 



If we compai'O the numbers, obtained after an immersion in NaCl 

 0.7",'o and 0.9%, it appears, that the difference in concentration ha? 

 exercised no influence on the vohime of the cells, but it has with 

 respect to the Na Cl-solutions 0.9% and I.So/q. 



It was possible that the Na CI- solution 0.9 % and 1.2 «/o had 

 therefore caused some contraction, as half an hour's immersion had 

 been insufficient to effect a complete exchange between the contents 

 of the cell and its surroundings. 



Under this supposition it seemed to us recommendable to ceutri- 

 fugalize the now remaining, but already two-hours old mixtures. 



Salt-solutions employed. 



NaCl-soI. of 0.7Vo 

 * // // 0.9V„ 

 « . ; 1.20/„ 



Volume of the epithelium. 



While thus after half an hour's immersion the difference in volume 

 of the epithelium, lying in 0.9 °/o and 1.2 "/u Na Clsolution amounted to 



— — — X 100 = 1 S^/o, this difference, after two hours amounts only to 



86—83 



X 100= ±40/0. 



86 



It appears thus, that after a sufficiently long immersion of the 

 epithelium in salt- solution, the difference in concentration exercises 

 no influence on the volumina. 



Of the many experiments, made in this direction, I will add two. 



Experiment XXII. 



Epithelium from the trachea of a horse just killed, distributed in 

 serum and afterwards in salt-solutions. 



Proceedings Royal Acad. Amsterdam. Vol. I. 



