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From diseased pods of Phaseolus vulgaris, 4 strains were isolated of Colletotrichum lindemuthianum: Z I and Z II from Zeeland; E from Enkhuizen; W from Westland. The strains differed from the American strainsβandγ. Tests on bean varieties used by Leach suggested that Z strains were related to form VIII of Leach and strains E and W were identical with forms IV and V. The Dutch strains differed in both severity and manner of attack on test varieties of bean, and in lethal and optimum temperatures. The fungus overwintered in the soil and could survive severe cold, -15° or -20 °C, for 10 days. Especially in light, cultures at least 2.5 months old produced perithecium-like bodies containing structures resembling asci.From diseased pods of P. multiflorus growing under apple-trees, a strain (K) was isolated and identified as Gloeosporium fructigenum because it attacked apples but was only mildly pathogenic on a few varieties of P. vulgaris. It was named f. hollandica because it was distinct from the forms germanica and americana. Passage of K through apple or tomato increased its virulence to them, while passage through P. vulgaris decreased virulence to fruit and increased that to bean. After adaptation to apple, properties of strain K on tomato was the same as C. lindemuthianum.

Among 70 Verticillium strains isolated from different hosts throughout the Netherlands, only 2 had the bundled dark hyphae described by Reinke and Berthold (1879) as characteristic of V.albo-atrum Reinke & Berth. This species was morphologically the same as V. dahliae Klebahn. The name V.albo-atrum had priority.Strains with loose dark hyphae (d.m. type) were less resistant to warmth (35øC) than those with microsclerotia (mscl. type). On artificial media all strains produced toxins, specific for each strain but not correlated with type or pathogenicity. The fungus spreads through the plant's vessels as spores or mycelium. The physiological range confirmed that there was no clear distinction between the two species but demonstrated a difference between mycelial and microsclerotial types. Host range was not limited (contrast Nelson, 1950; Isaac, 1957). Culture on tomato changed the virulence.Both types could spread in sterile soil between roots of antirrhinums only as hyphae. After 4 years in the soil only the mscl. type was slightly infective.Microsclerotia were assumed to be merely storage organs because they did not germinate, even with root secretions.After an infection resistant crops should be planted and possible carrier weeds eradicated. Use of resistant varieties was difficult because of differences in pathogenicity of Verticillium strains but chemical control was inadequate.

Rabbits were immunized with different preparations of F. oxysporum.Antibodies against culture fluid, homogenized mycelium, mycelial extracts and microconidial suspensions reacted in precipitin tests with both culture fluids and mycelium extracts.Cross reactions between formae speciales were very common. The gel diffusion precipitin test proved most suitable to differentiate formae speciales . Most sera did not specifically differentiate formae speciales . However some reacted highly specifically.Concerning the character of the antigens it was concluded that the mycelium contained glycoproteins. The glycoproteins split up into polysaccharides and various proteins both during autolysis in the cultures and during extraction of the mycelium.Rabbits only produced antibodies against proteins after injection with culture liquids or with saline extracts of mycelium. These proteins varied widely in physical properties and it was very difficult to reproduce the same proteins, even by the same extraction procedure. The polysaccharides were much more stablebut antibodies against them could be obtained only by immunization with microconidia. Probably these polysaccharides were present on the surface of the cell wall of the microconidia.The study demonstrated that the polysaccharides from the glycoproteins of Fusarium oxysporum were haptens.

Rabbits were immunized with different preparations of F. oxysporum.Antibodies against culture fluid, homogenized mycelium, mycelial extracts and microconidial suspensions reacted in precipitin tests with both culture fluids and mycelium extracts.Cross reactions between formae speciales were very common. The gel diffusion precipitin test proved most suitable to differentiate formae speciales . Most sera did not specifically differentiate formae speciales . However some reacted highly specifically.Concerning the character of the antigens it was concluded that the mycelium contained glycoproteins. The glycoproteins split up into polysaccharides and various proteins both during autolysis in the cultures and during extraction of the mycelium.Rabbits only produced antibodies against proteins after injection with culture liquids or with saline extracts of mycelium. These proteins varied widely in physical properties and it was very difficult to reproduce the same proteins, even by the same extraction procedure. The polysaccharides were much more stablebut antibodies against them could be obtained only by immunization with microconidia. Probably these polysaccharides were present on the surface of the cell wall of the microconidia.The study demonstrated that the polysaccharides from the glycoproteins of Fusarium oxysporum were haptens.