• Barker, K. R. & Walker, J. C. (1962). Relationship of pectolytic and cellulolytic enzyme production by strains of Pellicularia filamentosa to their pathogenicity. Phytopathologv, 52, 1119.
  • Bateman, D. F. (1963). Pectolytic activities of culture filtrates of Rhizoctonia solani and extracts of Rhizoc-tonia-iniected tissues of bean. Phytopathology, 53, 197.
  • Brow'n, W. (1915). Studies in the physiology of parasitism. I. The action of Botrytis cinerea. Ann. Bot..
  • Cantino, E. C. (1956). The relation between cellular metabolism and morphogenesis in Blastocladiella. Mycologia, 48, 225.
  • Cruickshank, I. A. M. & Perrin, D. R. (1963). Studies on phytoalexins. VI. Pisatin: The effect of some factors on its formation in Pisum sativum L. and the significance of pisatin in disease resistance. Aust.J. biol. Sci., 16, III.
  • Demain, A. L. & Phaff, H. J. (1957). Recent advances in the enzymatic hydrolysis of pectic substances. Wallerstein Labs. Commun., 20, 119.
  • Deuel, H. & Stutz, E. (1958). Pectic substances and pectic enzymes. Advanc. Enzymol., 20, 341.
  • Downie, D. G. (1940). On the germination and growth of Goodyera repens. Trans. bot. Soc. Edinb., 33, 36.
  • Downie, D. G. (1959). The mycorrhiza of Orchis purpurella. Trans. bot. Soc. Edinb., 38, 16.
  • Fåhraeus, G. & Ljunggren, H. (1959). The possible significance of pectic enzymes in root hair infection by nodule bacteria. Physiologia Pl., 12, 145.
  • Gäumann, E., Nuesch, J. & Rimpau, R. H. (1960). Weitere Untersuchungen uber die chemischen abwehr-reaktionen der Orchideen. Phytopath. Z., 38, 274.
  • Ham, A. M. (1962). Studies on vesicular-arbuscular endophytes. IV. Inoculation of species oi Allium and of Lactuca sativa with Pythium isolates. Trans. Br. mycol. Soc, 45, 179.
  • Harvais, G. (1963). Investigations of the mycorrhiza of Orchis purpurella and other British orchids. M.Sc. thesis. University of Aberdeen.
  • Leal, J. A. & Villanueva, J. R. (1962). Lack of pectic enzyme production by non-patbogenic species of Verticillium. Nature. Lond., 195, 1328.
  • Pérombelon, M. (1963). Pectic enzyme production by parasitic and endophytic Rhizoctonia strains. M.Sc. thesis. University of Aberdeen.
  • Roboz, E., Barratt, R. W. & Tatum, E. L. (1952). Breakdown of pectic substances by a new enzyme from Neurospora. J. biol. Chem., 195, 459.
  • Townsend, B. B. (1957). Nutritional factors influencing the production of sclerotia by certain fungi. Ann. Bot. N.S., 21, 153.
  • Waggoner, P. E. & Dimond, A. E. (1955). Production and role of extracellular pectic enzymes of Fusarium oxysporumf. lycopersici. Phytopathology, 45, 79.