I HAVE always thought of these pieces as spring jaunts," says Anthony Bailey in his preface to this exhilarating collection of his New Yorker travel articles, "but as I assembled them for this book I realized that not all of them took place in spring. It was the mood of spring that impelled me rather than dates in the calendar." The spirit of spring does indeed invigorate each of these five accounts of excursions made by Bailey into territory that intrigues him for personal or historical reasons, and his staccato style and ravenous eye for natural detail (particularly of flora) reinforce this mood to quickly dispel the languors that can creep in as spring gives way to muggier and doggier days.

Bailey was born in England, then came to the United States as a child during World War II and has been dividing his time between the two countries ever since. As a jaunter, however, his heart is still clearly in the British Isles: explorations of the Isle of Wight (birthplace of Bailey's father), the banks of the Boyne River in Ireland, and the Severn River in Shropshire fill the larger part of Spring Jaunts, with accounts of sojourns along the seacoast of New Hampshire (at 18 miles the shortest of any state touching salt water) and the Promenade des Anglais in Nice providing briefer glimpses of the USA and France.

History and the natural environment are always much on Bailey's mind as he makes his way through these primarily rural landscapes, and his narratives are crowded with historical anecdotes and sharply observed descriptions of the passing scene. As he trudges along the overgrown banks of the Boyne with the Irish poet Seamus Heaney, he revels in the profusion of plant life: "There was mint and gorse, iris and forget-me-not, cow parsley and celandine; big oxeye daisies; meadowsweet and charlock; ragwort, herb Robert, yellow flag and marsh valerian. Lovely words! . . . " and soon adds the plants' local names, learned from Heaney, to his list. Historical landmarks like Trim Castle (King John, Richard II and Henry V all stayed there, the last-named as a child of eight; and Swift's Stella studied in a school right across the river) and the legendary Hill of Tara are on every side, and Bailey's love of lists and of casual but profuse detail give his account unusually clear focus.

But best of all is the book's final piece, a chronicle of a trip down the Severn River in England made by Bailey sitting in a coracle -- a small basket-shaped boat made of a membrane stretched over a flexible wooden frame -- given to him as a birthday present by his wife. Somehow Bailey manages to include in his 68 hypnotic pages an overview of the huge literature and lore of the coracle, an ancient vehicle which has been in use since earliest recorded history (descriptions can be found in Julius Caesar's writings and in the Froissart Chronicles), the technology of its construction, a masterful portrait of Eustace Rogers, "probably the last coracle-maker in England, if not the entire British Isles," and an exciting narrative of his trip to Eustace's home at Severnside at Ironbridge, Shropshire. When, after many scrapes, he arrives, the surprised Eustace greets him by saying, "You've done very well." Few readers will disagree. A NATURAL HISTORY OF SEX; The Ecology and Evolution of Sexual Behavior; By Adriaen Forsyth, Scribners 190 pp. $16.95

READERS witha bent for anthropomorphism will find plenty to gasp at in Adrian Forsyth's tour of some of the more grotesque mating procedures that have evolved through the priorities of natural selection. Right now there are bedbugs being driven by sperm competition to engage in activities that make the worst of Sade seem merely naughty:

"The female bedbug is fitted with a seemingly normal genital tract. The male, however, is outfitted with an outlandish, formidable penis, which he wields in an almost perverse manner. His instrument of insemination is a swordlike stabber that he drives into the female's abdomen, of all places. And although this seems off target he ejaculates there nonetheless. The act is known, appropriately enough, as 'traumatic copulation.' "

Of course, this all works out for the best. The female has means to plug up the wound, and uses the excess ejaculate for nutrition. Even more abandoned are certain bedbug species in Africa, whose males commit a similar form of rape against other males. The point is that the rapist's sperm takes up residence in the victim's vas deferens, so that when he mates he will actually deliver some of the rapist's sperm.

This is only one of hundreds of examples Forsyth gives, many of them far more complex and bizarre than these bedbug antics. This material is astonishing for the uninitiated, and Forsyth plays it for all it's worth. Each chapter begins with a teaser sentence that serves as an irresistible baited hook: "Mothers have a habit of murdering their children";"Human females are sexually unpredictable";"Everyone is a victim." And he knows when he's hitting close to home. He has special fun dealing with aspects of human sexuality that are analogous to, or extensions of, the sort of behavior that so livens up trips to the zoo.

But despite the flashy writing and a palpable delectation in phenomena that the unjaded layman is invited to find shocking, this Natural History should be read seriously and carefully. Forsyth's real subject is the nature and effect of selection in evolutionary development, and in offering his insights he takes on, and convincingly discredits, pronouncements made by such big guns as Konrad Lorenz and Claude Le'vi-Strauss, neither of whom has been above a little stylistic horseplay of his own. No one will put the book down without pondering once again the vast complexity and seeming arbitrariness of the behavior that humans and bedbugs alike have no choice but to perform, and around which they construct so much of their lives. HOW TO DEEPFREEZE A MOMMOTH By Bjorn Kurten Columbia Univ. Press 160 pp. $ 167.95

SWEDISH paleontologist Bjo rn Kurte'n is so amiable and relaxed in this collection of popular essays on various aspects of paleontology that it's easy to forgive him for exploding everybodys' favorite mammoth myths. No frozen mammoth, he reports, has ever been found in an even remotely edible state; no one, as far as is known, has ever feasted on the meat of a mammoth excavated freezer-fresh from the permafrost. The origin of these mammoth-chop yarns was probably an attempt to eat some of its meat made by one of the scientists who excavated the Beresovka mammoth in 1900. "One of them made a heroic attempt to take a bite out of the 40,000-year old meat," Kurte'n writes, "but was unable to keep it down in spite of a generous use of spices."

Further mammoth disinformation was perpetrated by Ivan T. Sanderson in a 1960 Saturday Evening Post article. According to his "fantastic scenario", volcanic activity triggered atmospheric turbulence which brought down bubbles of gas chilled in the stratosphere to such low temperatures that the mammoths were flash-frozen clean through, "perfectly preserved to the last detail." Nonsense, says Kurte'n, all mammoths unearthed so far have been badly putrified inside, and none of the tissue has been well enough preserved to permit the cloning so eagerly awaited by the mammoth science-fiction set.

Mammoths are only one of many subjects discussed in Kurte'n's book. Plate tectonics; the shady dealings which followed the discoveries of the first fossil Archaeopteryx skeletons; the Piltdown Man hoax; the geology of the great flood which occurred when the completely dried-up Mediterranean Sea, which had turned into an enormous valley that may have been inhabited by the first proto-men, suddenly refilled, creating what Kurte'n calls "perhaps the most colossal deluge that has ever hit any part of the globe"; and the inspiration and esthetics of cave art all become the centers of informal but highly authoritative discussion. Kurte'n does give the recipe for freezing a mammoth, by the way,and although he has never tasted mammoth meat, he was one of a group of paleontologists who cooked up a stew from the meat of a Bison priscus which had been frozen 36,000 years earlier. "The taste was agreeable," he writes, "and none of us . . . suffered any bad effects of the meal which meant that a number of organic molecules were returned to the biosphere after a thousand generations!" INCREDIBLY STRANGE FILMS; EDITED BY JIM MORTON, RE/SEARCH. 224 pp. $15.

FOR A CERTAIN faction of movie addicts, Russ Meyer's Faster, Pussycat, Kill! Kill! will always be a far greater film than Eisenstein's Battleship Potemkin, and Ed Wood's Glen or Glenda and Plan Nine from Outer Space are worth hundreds of viewings each. These fans have long since memorized all of the entries in Michael Weldon's gigantic Psychotronic Films the way medieval monks memorized the entire Bible, and cherish their VHSs as tools to be used for exploring unclassifiable movies very few theaters would consider running at all, and even then only after midnight. Jim Morton's new compilation of data on these films and interviews with their directors has a ready audience among devotees of the most extreme of fringe cinema, those who dismiss The Texas Chainsaw Massacre as too mainstream, and in this volume, as in the speciality video stores they haunt, they will find material they can see nowhere else.

Most interesting of the pieces included are the interviews with directors. Larry Cohen, director of the horrific God Told Me To, is snappily sardonic as he explains that his inspiration for the film came while walking through museums full of grisly religious art. "There's nothing as violent as the Bible," he says. "God kills everybody - drowns the entire world, destroys the cities of Sodom and Gomorrah, burning people to a crisp. 'This is a tough guy,' I said. 'Boy,if he ever comes back, look out!. . . He's one tough cookie. This man is strict.'" Cohen's astonishment at the violence in the religious paintings of the old masters was so great that he originally intended to use the canvasses as backdrops for the opening credits of his horror film.

Readers who are not true believers had best be prepared for a certain amount of hyperbole. "Forget Birth of a Nation, forget Citizen Kane," advises Jim Morton at one point. "(Russ Meyer's) Beyond the Valley of the Dolls is the great American movie." But even those in no special hurry to catch up on women-in-prison genre films or to scour the video shops for a copy of Spider Baby will not put this book down unintrigued. Crass as some of them are, most of these incredibly strange directors would retire their cameras rather than offer up the kind of ennui-by-the-yard that fills such upmarket films as Out of Africa and Terms of Endearment, and that sole virtue is a pearl above price shining through all the trash. KOKOSCHKA A LIFE; By Frank Whitford, Antheneum. 221 pp. $21.95

THIS year is the centenary of Oskar Kokoschka's birth and there will be several opportunities to survey the life and achievement of this Viennese-born painter and dramatist, whose stylistic innovations in the first decades of the century provided much of the vocabulary for German Expressionism. The Guggenheim Museum in New York is mounting a retrospective exhibition of his work, and Atheneum has published this new biography, the most comprehensive to have appeared in English.

Whitford's emphasis is more on the artist's life than on the technical development of his work. Like so many of the great modernist creative figures who developed their ideas and styles in turn-of-the-century Vienna (Scho nberg, Wittgenstein, Freud, Karl Kraus et.al.), Kokoschka put a great deal of energy into an ongoing love-hate relationship with the city. The Viennese, always among the very last to appreciate the greatness of their geniuses, rejected him outright, and he was forced to take his revolutionary ideas to the more receptive artistic circles in Berlin and, eventually, Paris.

The exasperations of Kokoschka's early career, painful despite the enthusiastic support of such figures as the architect Adolf Loos and journalist Karl Kraus, were matched by the tribulations of his personal life. Like a long queue of other creative artists, Kokoschka became passionately involved with Gustav Mahler's fast widow Alma who, as Whitford writes, "found talent erotic." She tormented him, aborting his child without consulting him and two-timed him with the architect Walter Gropius even as Kokoschka was hospitalized with near-fatal head wounds sustained on the battlefields of the First World War. Although Whitford gives a fairly thorough account of the artist's later years when, living in exile from the Nazis in England with his wife Olda, he resisted trends toward abstractionism and occupied himself with relatively conservative landscape painting, the main focus of the biography is on the groundbreaking earlier years.

In the acknowledgements at the end of his book, Frank Whitford admits that his book "cannot claim to be definitive. The moment for a more comprehensive and detailed life will come only with the publication of all the artist's letters, with the gathering of more documentary evidence about his friends and colleagues and with the completion of a thoroughly revised catalogue of the artist's complete oeuvre." For the time being, however, his biography will serve well, as it provides much new information on one of the chief architects of German Expressionism. Bob Halliday writes frequently about contemporary music and literature.