VERSTER, ANNA, COLLIN S, H . MARIA & ANDERSON, P. J. S. 1971. Studies on D ictyocaulus filaria. IV. The morphogenesis of the parasitic stages in lambs. Onderstepoort ]. vet. R es. 38 (3), 199-206 (1971). In males the parasitic 3rd stage, 3rd moult, 4th stage, 4th moult and 5th stage are reached on D ays 1 to 2, 3, 4, 5 to 6 and 8 respectively. The 4th stage is swollen in the anal region and acc...