226 



SCIENCE 



[N. S. Vol. XLII. No. 1076 



tion becomes more prominent, betraying itself 

 by the greater tendency of the tissues to li- 

 quefy and, since hydration is now less, by soft- 

 ening. 



The experiments also bear upon the problem 

 of digestion and that special phase of it known 

 as autolysis. The first changes observable in 

 these reactions consist of swelling, followed 

 by softening and dissolution of the proteins 

 acted upon. Acids and alkalies have long been 

 known to favor these initial steps in proteolysis, 

 while salts have been known to inhibit them. 

 Their action has usually been laid to the effect 

 upon the enzymes themselves. As has been 

 pointed out before,* acids, alkalies and salts 

 produce at least as large and probably their 

 greatest effects upon the proteins undergoing 

 digestion. The important practical and theo- 

 retical bearings such considerations have upon 

 laboratory practise and in the every-day prob- 

 lems of the hanging of meat, its preservation 

 by salting, the prevention of putrefaction, etc., 

 is self-evident. 



The experiments also reemphasize the neces- 

 sity of interpreting in the simpler language 

 of colloid-chemistry the mass of experimental 

 material now jumbled under the heading of 

 "permeability" studies. It means little to 

 say that under the influence of acids or of 

 substances which in living cells produce acid 

 effects (like the anesthetics) the "permeabil- 

 ity" of the "plasma" membranes surround- 

 ing cells is increased so that albumin gets out 

 or salts get in. Not only are plasma mem- 

 branes figments of the imagination, but noth- 

 ing is gained by heaping "permeability" 

 properties upon them. "Permeability" is a 

 physiological concept which needs itself to be 

 explained. The proteins throughout a cell 

 (not only in its hypothetical overcoat) can 

 under the influence of acids, for example, be 

 made to absorb water, to absorb salt,^ to soften 

 and to give off albumin. And as all these ef- 

 fects can be reduced through the addition of 

 various salts, there would seem to remain little 

 reason to ignore for the interpretation of well- 



4 Martin H. Fischer and Gertrude Moore, Am. 

 Jour, of Physiol, 20, 330 (1907). 



5 Martin H. Tiseher, Jour. Am. Med. Assoc, 64, 

 325 (1915). 



known biological facts the simple principles of 

 colloid-chemistry. Martin H. Fischer 



Joseph Eichbebg Laboratory of Physiology 

 IN THE University of Cincinnati 



SOCIETIES AND ACADEMIES 



SECTION OP biology AND GEOLOGY 

 ACADEMY OF SCIENCE AND ART OF PITTSBURGH 



During the year 1914-15 the Section of Biology 

 and Geology of the Academy of Science and Art of 

 Pittsburgh held fifteen meetings with an average 

 attendance of about 150 members. The general 

 topic under discussion was Evolution and the fol- 

 lowing papers were presented: 

 October 6, 1914. Dr. Prank Schlesinger, Director 

 of the Allegheny Observatory: "Evolution of 

 the Universe." 

 October 20. Professor Henry Leighton, of the 

 University of Pittsburgh : ' ' The Earth 's History 

 and Development. ' ' 

 November 3. Dr. Chas. R. Fettke, of the Carnegie 

 Institute of Technology: "The History of the 

 Eocks. ' ' 

 November 17. Dr. A. E. Ortmann, of the Carnegie 

 Museum : ' ' The Direct Evidence for Evolution. ' ' 

 December 1. Dr. O. E. Jennings, of the Carnegie 

 Museum: "The Evolution and Ecology of 

 Plants. ' ' 

 December 15. Dr. A. E. Ortmann: "Evolution in 



Animals. ' ' 

 January 5, 1915. Professor L. E. Griffin, of the 

 University of Pittsburgh: "Embryology in its 

 Eelation to Evolution." 

 January 19. Dr. W. J. Holland, Director of the 



Carnegie Museum: "Paleontology." 

 February 2. Professor Eoswell H. Johnson, of 

 the University of Pittsburgh: "Experimental 

 Evolution. ' ' 

 February 16. Mr. O. A. Peterson, of the Carnegie 



Museum: "The Evolution of Man." 

 March 2. Mr. George Seibel: "The Evolution of 



Society." 

 March 16. Professor L. E. Griffin: "Ant Be- 

 havior. ' ' 

 April 6. Professor Gardner C. Basset, of the Uni- 

 versity of Pittsburgh: "Heredity." 

 April 20. Dr. H. B. Davis, principal of the Train- 

 ing School for Teachers: "Evolution in Educa- 

 tion." 

 May 18. Eev. Charles E. Snyder: "The Evolution 

 of Eeligious Thought." 



Charles E. Fettke, 



Secretary 



