earlier references are listed there. Also in the transport problem, in Momentum Transfer, Hre. is negligible; see Parikh, J.,4 Appendix B. 6 Allowing A to depend on w2 [see Bardeen, J., Rev. Mod. Phys., 34, 667 (1962), Appendix BI does not affect the main part of our argument, concerned with terms linear in w. 7 Note that, contrary to our notation, the momentum of a quasiparticle of "type 1" (spin-) is called-k in ref. 4. 8 The condition owkF << 1 in equation (16) sets an upper bound to Jv| but still admits fairly large values of In 1vi (.10, say).

No abstract

Sumimiiary. Calcium (or miagnesium) sulfate or chloride was found to inhibit energy dependent ipotassium transport in excised corn roots. This Ca"t inhibition of K' transport was most pronounced during the initial phases of transport. As the absoription periods vere tengthened the effect of Ca 2 gradually changed from an inhibition to a typical promotion (after about 30-45 mins) of K' transport. Kinetic anaiysis indicated the inhibition to be of a non-competitive nature.Identical experiments with excised barley roots showed that CaS,O4 had no effect on K' absorption whereas CaCl9 had a typical stimulatory effect on K+ absorption. Kinetic (4,9,14,20). Rb+ (5,17,18,19), , Cl-(3, 15), SO042 (11) and P043-(12,17, 18). Scditim and lithiulm absorptioni, on the other hand, are drastically curtailed 1! Ca24 (4, 5,10, 16). However, the g'enerallx-prometive effects of (a21 on1 mononovalent cation absorpt on. plus the finding that Ca'2 appears to be essent-al for maintaining the integrity of the se'ectixe ion tranisport mechanisms (4). as well as the fact that (a2+ is necessary for the maintenance of cellular miemnbranes (13)

In studyiing the salt relations of l)lants, particular importance attaches to sodliulmi chlori(le. the predominant salt of the oceans and as well the main salt of the earth, in the arid and semi-arid regions of the world.

Abstract. Experimental conditions which optimize both substrate-and ATP-dependent Ca2+ transport in corn (Zea mays) mitoohondria have been determined. It has been found that a substrate (pyruvate + suceintaite) dependent, Pi independent, binding of Ca2+ occurs.This reaction is very rapid and complete in less than 30 6econds. For massive accumutlation of calcium, Pi is essential. Phosphate is accumulated along with the calcium and the ratio of Ca :Pi accumulated is about 1.6:1 indicating the precipitation of hydroxyapatite inside the mitochondria.The activation energies aind Michaelis constants for both the substrate-and ATP-driven reactions have been determined. It has also been shown that the substrate-driven system is more efficient in Ca2' accumulation than the ATP-driven system. This is partialily due to the fact that Mg2+ is essential for the ATP-driven system but not for the substrate-driven system and that Mg2+ acts as a strong competitor of Ca2+ transport. The effect of other inorganic ions on Ca2+ transport energized by both substrate and ATP were examined.The results lend support to the hypothesis that high energy intermediates of oxidative phosphorylation participate directly in Ca2' binding and transport in plant mitochondria.Plant mitochondria (7,9,10,11,12,14,18,19)