68 D. G. Crosby and A. J. Vlitos 



Dr. Galston: We have been interested in the differences in grow th 

 characteristics between completely etiolated pea sections and those 

 which have received a prior exposure to morphogenically active red 

 light. It has been reported that the surface characteristics of peas and 

 of other plants could be markedly affected by the degree of prior ex- 

 posing to red light. By an ingenious carbon-casting technique, flakes 

 and scales were seen on the surface of plants which were waxes. They 

 may contain some of these growth-active materials. Are we, by virtue 

 of prior red light exposure, inducing the synthesis of more cuticular 

 wax on the surface of these sections? Are we then producing, in a 

 sense, artifactual growth promotions or inhibitions? 



Dr. Crosby: Dr. Galston, I think this is likely. One problem which 

 we have had in dealing with compounds such as docosanol and octa- 

 decanol is that we have no way to measure their aqueous solubility. 

 They are extremely insoluble; even surface tension measurements can- 

 not determine their solubility. How, then, can they act as growth 

 stimulants? In our bioassay, we rotate the sections for 20 hrs. and, 

 certainly, each section must become evenly coated with the alcohol 

 as it comes to the surface. It is interesting that we get a very definite 

 change of activity with concentration. This has been repeated many 

 times and on different occasions over a period of many months. \Vhat 

 is the cause of this growth stimulation? Perhaps the thickness of the 

 waxy material influences directly the growth of the sections. We don't 

 know. 



Dr. Thimann: Would any of these active materials be present in 

 lanolin that is normally used in the laboratory? Lanolin has long 

 been known to produce some small amount of growth and cell divi- 

 sion. 



Dr. Crosby: The esters of the long-chain fatty acids and straight- 

 chain fatly alcohols would be present as minor constituents in lanolin. 



Dr. Bitancourt: Is there any interaction between the fatty acids 

 and lAA? 1 ask because in attempts to get solutions of lAA that 

 would not decompose over a long period, we used air-free water cov- 

 ered by a layer of paraffin oil. Instead of getting the stability that 

 we expected, we found that our solutions decomposed more rapidly 

 or as rapidly as those that hadn't been protected. I am wondering 

 whetlier there coufil f)e some chemical change in lAA induced by the 

 hytlrocarbons from jjaraflin oils. The decomposition was clearly dif- 

 ferent from that wfiufi occurred in aerated solutions where we got 

 a brownish coloration, whereas we got a beautiful red coloration in 

 tlic- sohuion iliat was piotected f)y paraffm oil. 



Dr. Crosby: W'c have not tried such experiments on a chemical 

 basis. Ohl- would not c\p(.( I a long-chain fatty alcohol such as doco- 

 sanol U) stabili/c 1A.\. On the other hand, salts of our long-chain 



