Hyphal tips of Sclerotinia sclerotiorum grown on a carboxymethylcellulose agar medium were studied with interference contrast, phase contrast, and dark-field optics and with the electron microscope. Microbodies with hexagonal crystalline inclusions were most abundant in a zone 80–160 μ from the hyphal apex. It is suggested that these bodies are involved in synthetic and storage functions. Lipid bodies were identified by their fluorescence with Nile blue and by their refractivity using dark field optics. They were most abundant in the first 80 μ of the hyphal tip and are thought to originate in this zone. Nuclei were randomly distributed throughout the hyphal tip cell.