( 106 ) 



Na Cl solutions and mixtures of serum and water, considering them 

 quite sufficient to answer the question which at the outset inte- 

 rested me most. "Whence arises the equality of expansion and con- 

 traction of red and white corpuscles? A question which immediately- 

 led to another, viz., why are the cells expanded by hypisotonic and 

 contracted by hyperisotonic solutions? 



Now we may with Schwarz consider the contents of the cell 

 (exclusive of the nucleus) as a homogeneous mass, or with Remak, 

 KuPFFER, Flemmimg, Bütschli and many others, as a protoplasmic 

 mass intermingled with fluid. "What must happen then in the former 

 case, if in a Na CI solution of 1.8% we immerse a cell of which the 

 homogeneous contents corespond in hygroscopic power to a Na CI 

 solution of 0.<jo/o? This mass will then contract to one half. If it 

 is placed in a NaCl-solution of 1^ "/g the expansion must amount to 



1.5—0.9 

 ■ — X 100 = 66 °!q. If on the other hand, we place it 



in a NaCl-solution of 0.7 "/q the expansion must then amount to 

 ' "~ '' X 100 = 22%. What appeared though? That the con- 

 traction as well as the expansion amounts to much less, viz., respec- 

 tively 17.5 and 1 3 % (cf. former table). This leads us to the conclusion 

 that in the red and white corpuscles there must be a substance, 

 which has either no part in the hygroscopic power, or a smaller 

 one than the other ingredient, and the question then presents itself 

 to us, how are we to suppose these substances to be arranged. 



Of the different hypotheses which in this respect have been formu- 

 lated for cells in general, there is only one which has appeared satis- 

 factory to us. And this is the hypothesis of Bütschli ^). 



According to this hypothesis the cells consist of a protoplasmic 

 net the closed meshes of which lie close to each other, and 

 the contents of which is a fluid. From the fact that the percen- 

 tage of the contents of the cells in hygroscopic matter, notwith- 

 standing that salt- solutions of different degrees of strength are 

 brought in contact with it, remains the same, we may suppose that 

 the protoplasmic net is not permeable to salts, but only to water ^). 

 "We may further suppose that only the fluid contents represent the 

 hygroscopic power of the cell. 



') Cf. Bütschli, Untersucliungen iiber mikroskopische Schaume nnd das Protoplasma. 



-) If the blood-corpuscles are considered permeable to salts, a change in the 

 isotonic relations must then take place, for by this only is the immutability of the 

 water-attracting force of the contents of the meshes guaranteed. For what follows, 

 however, it is indift'erent which of these two conjectures is correct. The one men- 

 tioned in the text is certainly the simplest. 



