The paper deals with two of four fungi which have been recorded as the cause of anthracnose diseases of red clover. 1. Kabatiella caulivora (Kirchn.) Karak. ( Gloeosporium caulivorum Kirchn.). This fungus is widely distributed, occurring in various European countries and in the northern states of America. It has been recorded in eleven counties in England and Wales. Petioles, stems, and occasionally the blades of red clover are attacked, with the formation of characteristic lesions. On the stem these are dark brown to black with a lighter centre which may become hollow. The general result is one of shrivelled leaves and broken stems. The fungus is characterised by minute hyaline acervuli each consisting of a cluster of basidia-like conidiophores projecting only a short distance from the epidermis and bearing terminally a group of non-septate sickle-shaped conidia. Single spore isolations have been made and the pathogenicity of the fungus proved. The germination of conidia on artificial media is characterised by the early and repeated budding off of conidia and by the scanty development of mycelium. Growth on media resembles at first a bacterial streak. Later it becomes black and small pycnidia are developed. On the host the spore sends out a slender germ tube which grows at first in the cell wall immediately below the cuticle. Growth in the host is preceded by brown discoloration of the cell walls and eventually the cells have brown contents. The mycelium is almost entirely intercellular. In the field, late flowering clovers were found on the whole to be more resistant than the early flowering strains. Trifolium hybridum and T. repens have been infected experimentally, but T. incarnatum, Medicago lupulina, M. sativa and several other members of the Leguminosae appear to be immune. Seed artificially contaminated with the spores of the fungus gave rise to diseased seedlings, the fungus developing on the cotyledons and first leaves. 2. Colletotrichum Trifolii Bain & Essary. This species has not yet been reported outside the southern states of North America. The disease has been studied by inoculating red clover plants with spores from a pure culture received from America. Stems and petioles are attacked and the lesions are usually lighter in colour and do not develop a hollow centre like those produced by the previous fungus. Mycelium is plentiful in cells of the cortex, pith, and thin walled cells of the vascular bundles. It is largely intracellular. Acervuli are accompanied by numerous black setae. The spores are straight, cylindrical and produced singly on slender conidiophores which arise from a slight stroma. Germinating on nutrient media the conidia form bipolar germ tubes which branch and give rise to a circular growth of mycelium. This develops a dark pigment and on it arise pink acervuli of conidia and setae like those produced on the host. Appressoria are developed in culture and on the host immediately the spores germinate. Seedlings raised from seed contaminated with spores from a culture developed after three weeks the disease on hypocotyl and cotyledons. In addition to Trifolium pratense the disease has been produced on Trifolium incarnatum, Medicago lupulina, M. sativa and T. hybridum , the latter species showing most resistance. T. repens and T. medium (one experiment) gave negative results.