The influence of the ovaries on tubal function is known to be principally hormonal, but the influence of the fallopian tubes on ovarian function is still unclear. A few studies designed for other purposes and conducted on rabbits have indicated that tubal surgery may have repercussions on ovarian function. None of the researchers was able to demonstrate the mechanism of the perturbation, and other studies on chinchillas and rabbits suggested that ovarian effects of tubal surgery were absent or minor. Clinical observations relating to the question include the fact that in all series of salpingoplasties, the rate of conception is much lower than the rate of permeability, while in the case of anastomosis after ligation, the rate of conceptions never exceeds 80% although in the best series the rate of permeability approaches 100%. The significance of the findings is limited because of the many other factors involved. Some studies of ovarian function after sterilization have suggested lowered progesterone level, retarded maturation of the endometrium after some types of tubal occlusion procedures, and increased estradiol levels. Other studies have shown that the ovary sometimes functions normally despite resection or repermeabilization, absence of tubes and implantation of the ovary in the uterus, or existence of only 1 tube and the contralateral ovary, while diverse series have failed to find modifications in progesterone level after ligature. Experimental studies on the topic are limited and their findings are contradictory, so that no formal conclusion is as yet possible regarding tubal influence on ovarian function.