Life Cycle.

The sporocysts are probably ingested by the Oxycanus larvae, either with contaminated grass, or in the process of excavating the tunnel in the soil. It is assumed that the sporozoites escape from the sporocyst in the gut and enter the epithelial cells of the intestinal wall, later passing through the basal membrane and coming to lie in the body cavity, though still attached to the intestine. After the growth of the trophozoite is complete it becomes detached from the intestine and floats free in the body cavity of the larva. These free trophozoites or sporonts may then be observed to attach in pairs, at first only at one point on the circumference, but later fused into a spherical mass, with each sporont hemispherical in shape. Gametes are produced by each sporont and the dividing wall between the sporonts disappears to allow the fusion of the gametes to form zygotes, each of which gives rise to a sporocyst containing eight sporozoites. All these stages may be observed (except the intra-cellular trophozoite, which has not been seen) in the body cavity of the host larvae. The later stages, the gametocysts and the contained sporocysts, have also