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Pa'nzes strobus or P. resinom seedlings, 2 or 3 ears old, were illuminated in a closed chamber for 1 hour in the presence of c"&. This was followed by various periods up to 24 hours under different conditions of light and darkness. Then each seedling was divided into its shoot, stem, and roots, and these were extracted separately with 80% ethanol. The extracts were resolved first on resins into sugar, amino acid, and organic acid fractions and then resolved further by paper chromatography. The C14 content of various fractions and of the eluted comp u n d s was determined by plating and counting their aliquots. Ethanolinsolub%e residue was oxidized and counted as BaC140g.Eight hours after administration of the Cl4O3, 91 to 94% of the total C14 was found in the ethanol-soluble fractions of shoot, stem, or root. In shoots sugars were found to represent more than 95y0 of the ethanol-soluble photosynthate, with sucrose forming three-quarters of it. In stem and roots sucrose represented from 75 to 94% of the translocated photosynthate. Raffinose, glucose, and fructose were present in both stem and root.Seedlings with poorly developed root systems translocated less photosynthate to roots than those with good roots. Seedlings, which prior to the experiments were grown in full sunlight or 2500 ft-c artificial illumination translocated more photosynthate to roots than those grown in 6% of full sunlight or 250 ft-c artificial light. Stronger light during translocation itself also had a slight stirnulatory effect.Seedlings, which were illuminated in the presence of C1402 for 1 hour and then retained in a closed chamber for a further period of 7 hours, translocated a larger fraction of absorbed CI4 to their roots than comparable seedlings transferred to air after feeding C1400.'Manuscript

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As has been shown in an earlier paper (Slankis 1948). dichotomous branching may be produced in isolated pine roots by addition of exndates of mycorrhi/al fungi (e.g. species of Boletus) to tbe nutritive solution. Similar branching of pine roots occurs in nature, according to the investigations of Melin (1923) and others, in connection witb the formation of mycorrhiza. Further investigations (Slankis 1949) indicated tbat ^-indoleacetic acid might be one of the components of the fungous exudates which cause this hninclnng. [3-indoleacetic acid which is known to have a marked effect on root formation (Thimann 1948). produced in isolated pine roots not only a rich development of short roots hnt also dicholomous brancbing of the last roots formed. The question now arises: Do other substances of tbe so called «auxins" which have a strong inflnence on root-formation (Thimann I.e.) produce a similar branching? Up till now experiments have heen made only with a-naphthaleneacetic acid which, as is generally known (Zimmerman and Wilcoxon 19:^5, Zimmerman and Hitchcock 1935 and others), can produce a rich formation of adventitious roots, as well as enhance the branching of the root system.Five-months old pine roots were used in the experiments. The seeds had been collected from Uddheden (Varmland, Sweden), ahout 110 m altitude. The method of preparing tbe root cultures has previously been descri!>ed (Slankis 1948 a, p. 278). The nutrient sohiti(m contained the following organic and inorganic suhstances per litre redistilled water: 71,95 mg Ca(NO:(),,-4H2O, 20,47 mg MgSO,.7H,0, 10 mg KHoPO,, 1,66 mg FeCI^GHoO (according [40]