22L 



nutrient medium (agar) in the lower part of the apparatus. For 

 this purpose they employed the segmented tubes. At the lower 

 end of the first tube, the substance might diffuse into the sur- 

 rounding medium ; but they assume that the concentration of the 

 toxic substance would be greater in the succeeding tube than in 

 the surrounding medium. This however would not be the case. 

 From the lower end of the first segmented tube as a radius, the 

 substance would diffuse radially itnifonnly in all directions and 

 the concentration in the second tube would be equal to that in 

 the general body of the medium ; this state would be altered only 

 after the roots had commenced to develop in the second tube. Hence 

 at the time when the roots commenced to grow outside of the 

 general alignment of the tubes, there could be no difference in 

 the concentration of the toxic substance to account for the lateral 

 development. 



J. Walter Leather, 

 Agricultural Research Institute, 

 PusA, Bengal. 



PROCEEDINGS OF THE CLUB 

 October 8, 1907 



The first autumn meeting for the year 1907 was held at the 

 American Museum of Natural History. The meeting was called 

 to order at 8:30 by the secretary, and Dr. E. B. Southwick was 

 elected chairman. Eleven persons were present. 



The minutes for the preceding meeting, on May 29, 1907, were 

 read and approved, and the name of Dr. Forrest Shreve was pre- 

 sented for membership. The resignation of Miss Edith B. 

 Brainerd was read. On motion the secretary cast the vote of the 

 club electing Dr. Shreve to membership. 



The announced program consisted of informal reports upon 

 the summer's work and observations. In response to calls by 

 the chairman the following members made remarks : 



C. Stuart Gager : Remarks on the absence of undergrowth in 

 a hemlock forest. 



Hemlock seeds germinate freely under the parent trees, but 

 seldom attain a height of more than three or four inches. It 



