The Life-History of Syngamus trachealis (Montagu) v. Siebold, the Gape-Worm of Chickens

Abstract

(1) The female can and does lay eggs.(2) The eggs in the body of living worms do not develop beyond the 16-celled stage.(3) The eggs passed in the fæces of chickens are in the same stage of development as those in the uteri of the adult.(4) The eggs take about a week to develop and produce infective larva?, when cultured in well aerated water at a. temperature of about 25°C.(5) The embryos undergo only one moult before reaching the infective stage.(6) The second stage or infective larvae are generally ensheathed. They are non-climbers, do not penetrate the skin, and cannot resist dessication.(7) In the body of the host the larvae soon reach the lungs, where they grow considerably in size and undergo two further moults.(8) The final or fourth stage larvae are reached in about five days after infection.(9) The larvae then copulate and migrate into the trachea where they attain sexual maturity in from 10 to 14 days later.(10) The whole life cycle is completed within a month.