In Ascaridia galli larvae artificially hatched after 11 and 12 days of incubation at 25 degrees C, in larger frequency than in larvae hatched either after 10 and after 14 days of incubation, two different cuticles detached from their bodies were observed. These two detached cuticles indicate that such larvae had undergone two moults before hatching and, consequently, that the infective stage of A. galli is the third larval stage.