Hermaphroditism

In some relatively simple animals such as the earthworms and leeches, organs producing sperm and ova occur in the same individual (see Hermaphroditism). Although such animals produce both male and female gametes, the production of sperm and ova usually occurs at different times, so that these animals generally do not fertilize themselves but rather other individuals of the same species. Certain hermaphroditic animals, such as the planarian flatworms, habitually undergo self-fertilization. Among plants, one individual may bear reproductive organs of only one sex, separate reproductive organs of both sexes, or reproductive organs containing both male and female elements (see Flower). Individuals among higher animals bear reproductive organs of only one sex.