46 P. Larsen and T. Aasheim 



(15) : 2 g. of DMCA were dissolved in 100 ml. 6 N HCl plus 100 ml. 96 

 per cent ethanol. 



Plant Extracts 



Extracts were made as described by Larsen (21) . 



Pisum. 15 to 50 g. samples of the upper 10 to 15 cm. portions of 

 epicotyls of etiolated 7- to 9-day-old pea seedlings 'Alaska' were ex- 

 tracted at room temperature with 25 to 100 ml. portions of peroxide- 

 free ether. The ether was renewed twice after 24 or 48 hr. periods. The 

 3 portions of ether were reduced in volume and combined. A suitable 

 number of such extracts were combined, adjusted to a volimie of 

 about 12 ml., and shaken three times with 10 ml. HoO -j- 1 ml. 8 per 

 cent NaHCOg. The aqueous, alkaline fraction was discarded. The 

 ether fraction, now containing only the nonacidic materials, may be 

 tested in the Avena curvature test, but contains fatty materials in quan- 

 tities too high for a satisfactory application of concentrated droplets to 

 the starting line of a paper chromatogram. Most of these fatty mater- 

 ials were removed by the following method. The ether was evaporated 

 to dryness in a 50 ml. Erlenmeyer Hask. The residue is a smooth layer, 

 covering the bottom of the flask. This residue was dissolved in 2.5 ml. 

 96 per cent ethanol which was then evaporated off at about 45° C. 

 Probably on account of the water present in the ethanol, the residue is 

 now in the form of small flakes, which can be suspended in water. 

 Eight ml. water were added to the flask which was then shaken for 10 

 min. at 45° C. and cooled to 5 to 7° C. The suspension was filtered 

 through a coarse Pyrex sintered glass filter, using suction. The flask 

 was rinsed three times in this manner. The combined slightly opaque 

 filtrates, about 24 ml., were shaken with three 12 ml. portions of ether, 

 and the combined ether fractions were adjusted to a volume of 25 ml. 

 The content of fat in this ether extract caused no difficidties in 

 chromatographic work. 



Brassica. 50 g. of the inner, etiolated leaves of a head of cabbage 

 were extracted and treated as described above for Pisntii, except that 

 removal of fat by carrying the neutral fraction through water was 

 omitted. These extracts were used at much lower concentrations than 

 those of Pisum. 



Avena Coleoptilc Curvature Tests 



These tests were carried out as described by Larsen (23) . Avena 

 seedlings were grown individually in soil in vials and decapitated 

 twice. Ether extracts were transferred to 0.1 nil. agar platelets bv the 

 ether-dropping mctliod. 



