Experiments on insemination inMoniliformis dubius(Acanthocephala)

Some effects of insemination onMoniliformis dubiuswere studied by means of a surgical technique involving the transplantation of worms of known age, sex and reproductive state from one male rat to another. Insemination resulting in the development of eggs was found to have occurred in femaleM. dubiusaged 16 days. An individual maleM. dubiuswas found to be capable of inseminating as many as 17 females of the same age. The duration of the patent period appeared to be related to the length of the period of contact between male and female worms at the start of the course of infection. The evidence indicated that the patent period of a female worm was curtailed in cases where the female was isolated from males sooner than 5 weeks after the start of the infection. Male worms estimated to be not more than 21 days old were found to be capable of inseminating females older than 100 days; in these cases, the patent period was brief. Evidence was obtained to suggest that insemination is followed by further growth of the somatic tissues of the female worms. These results apply to experimental infections, and caution should be exercised in applying them directly to natural infections.