A prolonged preservation of Ascaridia galli eggs in acid medium when cultivating them under laboratory conditions inhibits considerably the establishment of Ascaridia galli in the organism of chickens. The neutralization of medium of egg cultivation 3 days before their application for infesting facilitates the increase of larvae established in the organism. 2. In chickens invaded with Ascaridia galli eggs cultivated in medium with pH 8.0, larvae develop in the period of 7--21 days of invasion in the amount of 2.5--69 times more than in chickens receiving the same eggs but which have been cultivated in acid medium (pH 2.2) for the whole cultivation period. 3. With the increase in invasion period, the number of established larvae decreases in both test groups, but in chickens receiving eggs which have been cultivated in medium with pH 8.0, the number of larvae is considerably higher.
