Inhibition of Ovulation in the Domestic Hen by

ARTIFICIAL insemination (A.I.) di-•** • rectly into the uterus has resulted in fertility under circumstances when none could be obtained with intravaginal A.I. Polge (1951) obtained no fertility follow-ing intravaginal A.I. with semen containing 15 % glycerol, but Allen and Bobr (1955) obtained some fertility when it was depos-ited directly in the uterus. Ogasawara et al. (1962) obtained fertility with the semen of two low-fecundity cocks only by intrauterine A.I. Intrauterine A.I. has been used extensively in studies of behavior of spermatozoa in the oviduct (Bobr et al., 1964a, b), but its usefulness in research has been limited, and any potential practi-cal applications curtailed, by the tendency of birds to pause after using this tech-nique. This paper places on record a number of observations on the effect of intrauterine A.I. on subsequent egg production and comments on the conditions that affect it. Intrauterine A.I. involves penetration of the uterovaginal junction. Allen and Bobr (1955) accomplished this with a 10.5 cm. long glass cannula and they suggested pre-liminary penetration with the forefinger to guide the cannula. For our work the can-nula was modified; it had a slight bend and a small plastic ball near the end to ai