METABOLISM AND THE DISTRIBUTION OF MATERIAL 243 



but not a distribution according to HENRY'S law, has been determined 

 by H. BECHHOLD in the action of disinfectants (see p. 399), and 

 STRAUB-FREUNDLICH on the distribution of veratrin between heart 

 muscle and pericardial blood. G. LOEWE has shown by simple 

 physico-chemical experiments that lipoids adsorb dyes, narcotics, 

 nicotin and tetanus toxin. The substance interchange in animal cells 

 has been studied most thoroughly in the case of red blood corpuscles. 

 In my opinion (see p. 304) the latter have a very peculiar struc- 

 ture, conditioned by their special function; their lipoid pellicle 

 is quite strong. In spite of this, we shall find phenomena in 

 the case of the erythrocytes which cannot be brought into accord 

 with the idea of a salt solution surrounded by a semipermeable 

 membrane. 



The theory of osmotic pressure demands that various isotonic salt 

 solutions shall have equal influence upon the volume of the blood 

 corpuscles. S. G. HEDiN* 1 showed, however, that this is not the 

 case, for instance, in isotonic solutions of NaCl and KNO 3 ; in the case 

 of lower concentrations, the volume is smaller; in the case of higher 

 concentrations it is larger than with the corresponding NaCl solu- 

 tion; we must recall that the N0 3 ion favors swelling or the de- 

 flocculation of colloids and lecithin; if the outer pressure is low, 

 crystalloids leave the blood corpuscles, and the osmotic pressure, and 

 consequently the volume of the corpuscles, will be less than with the 

 corresponding NaCl solution. The reverse occurs if the outer solu- 

 tion is hypertonic. 



We find in the literature, repeated references to the permeability 

 of the cell membrane, especially of plants, for potassium nitrate. B. 

 VAN RYSSELBERGHE* has demonstrated the entrance of diphenylamin 

 into tradescantia cells. If fungi, such as aspergillus niger or penicil- 

 lium glaucum, are grown upon a concentrated solution of saltpeter, 

 they will take up so much of the electrolyte that in the end they will 

 have an osmotic pressure of 200 atmospheres. Such cultures actually 

 explode when placed in pure water. 



The ability to take up such substances as favor swelling is much 

 greater in the case of young cells with membranes that can swell 

 than in the case of old inelastic cells. On this account, an older 

 aspergillus cell may plasmolyze with a 20 per cent NaNO 3 solu- 

 tion which possesses an osmotic pressure of only 102 atmospheres. 

 In this difference between old and young cell membranes, may lie a 

 partial explanation why bacteria and fungus cultures, namely organ- 

 isms which multiply rapidly, readily adapt themselves to changed 

 conditions. Young and old cells differ in their turgidity. 



R. HdBER* 6 prepared suspensions of blood corpuscles in dilute iso- 



