PROCEEDINGS OF THE CLUB 

 Meeting of May 19, 1937 



The meeting was held at the Boyce Thompson Institute for 

 Plant Research, and called to order by President Barnhart at 

 3:30 P.M. There were forty persons present. The minutes of 

 the last two meetings were read and accepted. 



The meeting was given over to the scientific program which 

 was supplied by the Institute staff. Dr. Zimmerman presented 

 the speakers who gave short resumes of their work. 



Mr. Setterstrom spoke on "The toxicity of air containing 

 sulphur dioxide and contaminated air about industrial centers," 

 describing a very elaborate apparatus which can detect one 

 part of sulphur dioxide in one hundred million. Four parts per 

 million were found to be toxic to plants. 



Miss Barton mentioned "Recent trends and a survey of 

 research on seed germination." She stated that there are two 

 reasons why seeds do not germinate: 1) because they have hard 

 seed coats; 2) because they have dormant embryos. Concen- 

 trated sulphuric acid can be used to break down the seed coats. 

 A period of storage at a low temperature is usually required to 

 break dormancy. 



Dr. Flint showed there was a relationship between "Light 

 sensitivity and seed germination." Although lettuce seed will 

 not normally germinate until spring, Dr. Flint found that by 

 exposing moist seed to bright light for one second he could get 

 100 per cent germination in twenty-four hours. Experiments 

 were conducted with light of various wave lengths. The seeds 

 were found to contain chlorophyl. 



Dr. Youden stressed the importance of "The recognition of 

 biological variation in designing experiments." He showed how 

 it was possible to determine accurately the effect of five solu- 

 tions on a plant by using five plants with five leaves each. 



Dr. Hitchcock spoke on "Growth promoting substances up 

 to date." He displayed tomato plants showing the systemic and 

 local effects of various of these substances. He stated that fifty 

 substances are now known to induce these reactions. An attempt 

 is being made to determine accurately how much more active 

 one substance is than another, using the degree of bending as 

 a method of measurement. 



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