The best-seller list has had a long, standing liaison with the medical profession: Besides the vets and the diet experts and sexologists in the nonfiction column there have been the many physicians -- dear, glorious and otherwise -- of the popular novel.

A. J. Cronin, Lloyd C. Douglas and Frank G. Slaughter are some of the best known of the writers who successfully dabble now and again in "doc fic," a genre in which two distinct strains can be isolated. On the one hand, there is the type of story which presents the white-coated, stethoscope-wearing hero as a martyred demigod who sacrifices almost everything to Healing: Sinclair Lewis' "Arrowsmith" falls into this first category. The second strain, best exemplified by Morton Thompson's "Not As a Stranger" (the No. 1 best seller in 1954), offers a glimpse behind the scenes of a hospital community, introducing such characters as the Alcoholic Anesthetist, the Incurably Ill Nurse and the Philandering Surgeon.

"Randon Winds" repeats the family-saga formula Belva Plain scored such a hit with two years ago in "Evergreen"; it is a doc-fic plot of the first kind, in which three generations of Farrells put M.D. after their name, each giving something up in the process. If Martin Ferrel is not quite Martin Arrowsmith, still he -- the middle Farrell medical, and the novel's hero -- has a vision of his calling which often puts him at odds with his peers. An idealist, he worships one woman and one concept of medical treatment ("all the neurological specialities . . . joined in one discipline under one roof"), yet events place him in two unfulfilling marriages and give him a busy practice which rewards him financially but not spiritually.

The story opens by zooming in on a snowy landscape; it's upstate New York, early in the century, and a country doctor is making his way in his buggy to visit patients. This is Enoch Farrell, M.D., father of the about-to-be-born Martin. A stock figure, the elder Farrell soon fades from the scene as the author indicates she intends to focus on his son, who is "'A quiet man . . . with a lot of restless energy' . . . a sensitive man, perceptive, tense, reserved, intellectual, kind, proud, ambitious." These qualities with which Martin Farrell is imbued give Plain some maneuverability with him: He's complex but predictably so. And as Martin speeds through medical school, internship and residency, the reader becomes fond of him, if not quite infatuated.

As Martin Farrell M.D., he marries the hunchback sister of the woman he passionately desires, moves to England becomes the father of a baby girl (later Clare Farrell, M.D.) and is involved in enough instances of bad timing and fickle fate to keep the rest of the novel moving on inexorably until the present.

Plain, the wife of a doctor, is a storyteller and accomplished one -- in the manner of Agnes Sligh Turnbull, Frances Parkinson Keyes and that master of doc fic, A. J. Cronin. Call it melodrama, call it soap opera; whatever the diagnosis, it fills the Rx for entirely pleasant but unmemorable entertainment.