A coroner who dropped a dead infant head-first onto the floor as part of his research into skull fractures is being sued by the child's parents for $2 million in a case that has divided doctors over such practices. Some coroners say such research has been carried out in morgues for years. Others say the permission of the next of kin should be required. In the trial, which began last month, District Judge Hugh Brunson must decide whether state law allows coroners to conduct experiments not needed to determine the cause of death and whether approval from relatives is needed. No state court has previously ruled on the issue. But state Assistant Attorney General Chuck Yeager said in an opinion last year that the law does not authorize such experiments without the permission of the next of kin. Dr. Charles Odom, a deputy coroner for Lafayette Parish in southern Louisiana, was fired by his boss, Coroner Robert P. Thompson, who found out about the experiment on 4-month-old Christina Arnaud and informed the parents. Dwayne and Ellen Arnaud are seeking damages for emotional suffering. The trial, which is being held in Lafayette, 95 miles west of New Orleans, is in recess but resumes in August. The baby died of sudden infant death syndrome in 1986, and an autopsy was performed by Odom the same day. Odom held the baby by the heels and dropped it onto a concrete floor. Findings from the experiment were later used in a manslaughter trial in Hawaii in which charges against a father accused of killing his child were dismissed. Odom, now an assistant medical examiner in Dallas, testified in the Hawaii trial that he believed the experiments on the infant and on another baby's corpse proved that children could die from skull fractures suffered during accidental falls from the arms of an adult. Testifying at the Lafayette trial, Odom said he regarded the experiment as proper and said such research is not uncommon. While the primary purpose of an autopsy is to determine the cause and manner of death, there is a secondary purpose _ ``to gain medical knowledge and use that medical knowledge in the service of the living,'' Odom said. Some doctors defended the practice. ``I think it's a good thing and a needed thing,'' said Dr. Terry Welke, Calcasieu Parish coroner. ``There's a lot of knowledge brought about by experimentation that is not allowed on the living. It's a good practice to allow it here.'' Odom and other medical examiners say that skin, bone, eyes, heart valves and kidneys are often removed from bodies and used elsewhere, with and without the knowledge of the family. Dr. Monroe Samuels, a medical examiner in Orleans Parish, said requests to experiment on corpses during autopsies are submitted regularly by medical schools and research centers in New Orleans. ``We would only do it if it did not deface or deform the body,'' he said. ``We do have requests for some surgical techniques, but those are only done with permission of the next of kin. We're not talking about ghoulish things like leaning on an arm to see how far it will go before it breaks or shooting a gun at it.'' Welke said that in his office, doctors have come in to practice techniques on cadavers before moving on to live patients. ``It's done basically because physicians are trying to enhance their knowledge,'' he said. ``If the practice is cut off, it would be a big problem.'' But Dr. Sylvan J. Manuel, St. Landry Parish coroner and president of the Louisiana Coroners Association, was one of a number of coroners who said they knew of no experimentation unrelated to the autopsy being done in Louisiana. ``I don't think any of us are doing it, or should do it,'' Manuel said. ``I don't think anything should be done without the permission of the family. If you're going to take something off the body _ a fingernail even _ you should have permission of the family.'' Jefferson Parish Coroner Robert Treuting testified that experiments such as the one conducted by Odom help doctors and researchers perfect operating techniques and find cures for illness. Treuting said orthopedists have practiced dissecting joints on cadavers awaiting autopsies, and researchers took some parts from a body to study hardening of the arteries. Pathologists have the right to do anything they want with the body, including keeping it, if there is a legitimate research reason, Treuting testified. But he said it would be callous for the survivors to be told of experiments because it would compound their anguish.