His right temple stitched and bandaged after a fall, Pope John Paul II argued today against abortion, euthanasia and prenatal medical intervention in a plea to his fellow Poles to respect human life.

The 79-year-old pontiff carried out two scheduled events in southeast Poland -- a Mass in the 7th century village of Sandomierz and a speech at a prayer meeting in Zamosc -- despite a fall suffered as he left the Vatican Embassy in Warsaw this morning that caused a head injury requiring three stitches.

Vatican spokesman Joaquin Navarro-Valls said there were "no neurological repercussions" or other effects of what he called a "slight contusion." He said he did not know what caused the pope to fall, at least the third such incident in the past six years.

In remarks today on abortion and euthanasia, the pope used some of the strongest language heard so far in the 13-day pilgrimage to his homeland that began June 5. He called such procedures signs of "a real contempt for man."

His condemnation of prenatal "interventions and . . . experimentation" apparently referred to medical procedures such as amniocentesis, which can detect genetic problems in a fetus. Right-wing Solidarity lawmakers in Poland are seeking to restrict the use of such tests as a way to prevent abortions.

The pope's fall came after a rigorous day, including major speeches to Parliament, the Polish bishop's synod and several meetings and prayer sessions.

The pontiff arrived in Sandomierz today with a bandage visible just below his skullcap. He had trouble climbing the stairs to his chair and was helped by two aides. But he sounded strong and did not appear to be in pain.

In Zamosc, a Renaissance town in the countryside, the pope spoke of the glory of creation, saying respect for "the laws of nature" needs to be extended to mankind itself.

As an audience of 150,000 applauded, the pope asked, "Is it really possible to oppose the destruction of the environment while allowing, in the name of comfort and convenience, the slaughter of the unborn, and the procured death of the elderly and the infirm, and the carrying out, in the name of progress, of unacceptable interventions and forms of experimentation at the very beginning of human life?"

CAPTION: Bandaged pope, 79, says Mass in the Polish town of Sandomierz.