190 



when a cell is transferred to a more dilute medium it swells and 

 becomes more turgid. Strong solutions tend to check vital ac- 

 tivity. Removal to a dense medium often materially alters the 

 form of growth of an organism, the tendency being to assume 

 short thick forms in the dense medium and longer and more slen- 

 der forms in the dilute one. With different substances that are 

 not poisonous the cell seems to give the same response when a 

 strength of each is used that would exert the same osmotic pres- 

 sure, showing that it is the pressure and not the character of the 

 substance that produces the effect. The extraction of water from 

 the cell means the concentration of the solution of all the various 

 salts and other dissolved substances that are contained in it. 

 Varying strengths of the same salt are known to affect the growth 

 of plants very diversely, and this suggests an interesting field for 

 further investigation. 



The paper brought out an interesting discussion as to the prob- 

 able effect on the aquatic vegetation of a gradual change from 

 fresh- to salt-water conditions, or vice versa. 



Mr. Earle discussed " Generic Limits among the Agaricaceae." 

 He called attention to the artificial character of the genera that 

 are now recognized and the unnatural grouping of species that 

 resulted from the use of only two or three characters as the bases 

 of genera. A more natural grouping would require that the 

 sum total of all the characters should be considered in defining 



genera. 



F. S. Earle, 



Secretary. 

 Tuesday, November io, 1903 



This meeting was held at the College of Pharmacy at 8 p. m.;- 

 Dr. Murrill in the chair; twenty-three persons present. 



The committee on admissions reported favorably on the names 

 of Miss Theresa G. Williamson and Dr. Phil. Voelkel, and they 

 were elected members of the Club. 



Mrs. Cunningham, of California, a prominent organizer in that 

 state of clubs for the preservation of wild flowers, was present 

 and by request exhibited a large collection of water-color sketches 

 of Californian wild flowers and spoke briefly of the best places 

 and seasons for findine them. 



