RECENT ADVANCES IN SCIENCE 387 



permeability depends upon the nature of the salt, and its con- 

 centration. The relation between concentration and the time 

 required to produce the arbitrary increase in permeability is 

 given by the equation 



log T =R-A-log C+ I, 



where T is the time, C the concentration and R and A are con- 

 stants, the latter depending on the electrolyte employed. The 

 method is only applicable to fairly high concentrations of the 

 salts used, 0*2 molecular potassium nitrate and potassium 

 chloride, o*o8 molecular barium chloride, 0*05 molecular barium 

 nitrate and 0*04 molecular aluminium chloride being the lowest 

 concentrations in which results could be obtained. These con- 

 centrations are, nevertheless, considerably less than those 

 employed by Hofler in his work noted above. 



In an interesting paper by K. Heusser (" Neue vergleichende 

 Permeabilitatsmessungen zur Kenntnis des osmotischen Ver- 

 haltnisse der Pflanzenzelle in kranken Zustande," Vierteljahrsch. 

 des Naturf., Ges. in Zurich, 65, 565-89, 191 7) the permeability 

 of the cells of leaves of Prunus persica attacked by the fungus 

 Exoascus deformans was compared with that of leaf- cells of the 

 same plant in the healthy condition. The measurements were 

 made by the plasmolytic method. It was found that the attack 

 of the fungus brings about a change in the cells of the host 

 so that the permeability rises to a maximum during the period 

 of most active growth of the parasite. 



Osterhout has continued his investigations on the electrical 

 conductivity of Laminaria disks under different conditions, 

 and has correlated changes in the conductivity with changes in 

 permeability. Among the questions examined by him by this 

 method is that of antagonistic effects, which he finds between 

 sodium chloride and sodium taurocholate (" Decrease of Per- 

 meability and Antagonistic Effects caused by Bile Salts," Journ. 

 Gen. Physiol., 1, 405-8, 1919) and between sodium chloride and 

 various alkaloids ("Antagonism between Alkaloids and Salts in 

 Relation to Permeability," /owrw. Gen. Physiol., 1, 515-19, 1919). 



AITTHBOFOLOGY. By A. G. Thacker, A.R.C.S., Zoological Laboratory, 

 Cambridge. 



In recent anthropological literature, first attention should, 

 perhaps, be given to the Proceedings of the Prehistoric Society 

 of East Anglia, of which the section for 1919-20 (vol. iii, pt. 2) 

 has just been issued. As readers of Science Progress are 

 aware, this society has been progressing most creditably during 

 the last few years, and the new Proceedings are even more 

 interesting than the earlier publications. The first article is 

 entitled " Man and the Ice Age," and is the presidential address 



