The corticosteroid content of cattle skin washings.

In vitro techniques have been developed to study the invasive processes of Fasciola gigantica. The conditions necessary for excystment were identical with those required by F hepatica. The ability of larvae to penetrate mouse gut in vitro was influenced by the composition of the fluid within the gut, and by the region of gut wall to which the larvae were exposed. Larvae remained viable on spleen cell monolayers for at least 60 days.