78 



structures again reappear in two days, and measure and behave 

 like the organisms in the original culture. It has been shown that 

 Bacterium tumefaciens can withstand drying and overwintering 

 in the field. The granular bodies which they form appear to 

 enable them to survive these adverse conditions. These bodies, 

 while not recognized as spores morphologically, nevertheless 

 seem to have some of the physiological characteristics of spores. 



An organism which produces spore-like bodies has been 

 found associated with Bacterium tumefaciens. It is mildly infec- 

 tious and tumor-producing. It grows abundantly without visi- 

 bly changing the character of the colony and produces spore- 

 like bodies in three to six days. 



The second paper, entitled "Bricks and Bubbles" was by 

 Dr. R. P. Wodehouse of the Arlington Chemical Company. 

 Following is the author's abstract: 



It is generally conceded that the tetrakaidecahedron is the 

 solid with the smallest surface area which is capable of parti- 

 tioning space, and it is the form which soap bubbles in masses 

 assume, and which the cells of many plants and animal tissues 

 tend to assume. Under the conditions prevailing in these cir- 

 cumstances the tetrakaidecahedron is therefore, the ideal 

 building block. 



The artizan, however, never uses such a building blcck in 

 the construction of walls and columns; for his purpose it would 

 be eminently unsuited. Instead, experience has taught him that 

 the ideal unit of construction for his purpose is a rectangular 

 block about twice as broad and three times as long as high. Both 

 kinds of building blocks are equally well adapted to the use to 

 which they are put; the uses, however, are different. In the 

 former case the block is required to sustain stresses which are 

 equal in all directions, while in the latter it is required to sustain 

 stresses which are unequal, since they are the result of the 

 vertical thrust of gravity, with little or no pressure in any other 

 direction. It may, therefore, be said that the tetrakaidecahedron 

 is the building block of equal lateral stresses, while the rectangu- 

 lar, brick-shaped hexahedron is the building block of unequal 

 lateral stresses. 



Marshall A. Howe 

 Secretary pro tern. 



