32 J. A. Bentley 



pigments remained was rejected. The rest of the chromatogram was 

 eluted with ether or alcohol, the cluate evaporated to a small volume 

 and then chromatographed. Figure 3B represents an extract chroma- 

 tograj)hed once in water, and Figure 3C represents a second wash- 

 ing of the same base line in water. It is evident that all the active 

 substances are not removed in the first washing. This has been noted 

 several times with heavily pigmented extracts. All activity is usually 

 removed from the base line by two washings. The difference in treat- 

 ments between OcJiromonas 1 and 2 may explain why zones X and 

 V were not detected in Ochromonas 1. 



Zone Z was eluted from chromatograms run at the same time as 

 that of Figure 3.A, and the eluates were rechromatographed in both 

 ammoniacal isopropanol and water (Figures 4A and B, respectively). 

 In both figures there is evidence that Z gives rise to another zone of 

 activity, probably zone X. Separation is not good in chromatography 

 in water, but if it is assumed that zone Z runs similarly to indole-3- 

 acetonitrile (IAN), then Z will be the large zone in the center of the 

 paper, and there is evidence of trailing to the solvent front, which 

 may be the production of zone X running at ajjproximatch the same 

 position as indole-3-acetic acid (lAA). 



The interconvertible auxins located in tomato and pea roots were 

 found in the ether-insoluble aqueous fraction, whereas the auxins in 

 the algae occur in the ether fraction. The ether-insoluble aqueous 

 fraction in the algae is very diduult to examine, as it is heavily pig- 

 menteil, besides containing large quantities of carbohydrates, amino 

 acids and other substances whith interfere with the bioassays. Pre- 

 liminary experiments on the aqueous fraction suggested that the 

 ether-soluble auxins may lie released to a limited extent from an un- 

 stable water-soluble (omijlcx by manii)ulati\e treatments during ex- 

 traction. To speed up this process, the aqueous fractions were treated 

 with alkali (A' .NaOlI at I") II). pressuic for 15 min.) and then ex- 

 tracted with ether. The resulting fractions are reierretl to as the sa- 

 ponified afjueous fractions. I'ndci these conditions bioassay has 

 shown thai no etlui-extiac table auxins are obtained from trvptophan. 



(;hromatography of the saponified acjueous fraction oi Odnotnotias 

 1 gave a /one similar to /one Z (Figure 5.\). On elution and rcchro- 

 matiography. this /one ga\e rise to a zone similar to zone X (Figures 

 5H and (.'.). Clu()matogia|)liy ol tlie sajjonified acpieous fraction of 

 Clilorrlld and ot C)< Inotnotuts 2 gave exactiv similar results. 



'I hus, etlier-solul)le (oin|)ounils simil.n in heha\ ior to those oc- 

 curring in the acidic ethei fiaciion (aii be oinained from the aqueous 

 eiher-insolul)le hadion alter treatment with alkali. 



It was thought iliai the intc-ic on\ii t ible auxins were acidic, as 



