The pendant of gold and enamel from the late 17th or early 18th century is curiously made. It is a skull, and if you move the hinged jaw, the rose diamond eyes open.

The memorial ring of gold and enamel forms a skeleton, a skull and crossbones and an hourglass incorporating a band of hair. Inscribed are the words, "W.H. Not lost but gone before No. 18 1661."

The bronze figure of a skeleton stands 16 inches high on a black base. The right foot rests on a book of Hippocrates; in the right hand is a skull.

The 16th-century German carved-ivory skull is portrayed as decomposing. Everywhere there are worms, snakes, scorpions and other vermin. A bird is pecking out an eye. The top of the skull is a screw-on lid. The sides are inscribed Hodi Michi Cras. Tibi. - Today to me, tomorrow to you.

There are more memento mori, or reminders of death, in the collection of Kenneth Jay Lane: skulls carved of ivory, pearwood, silver, alabaster, bone, rock crystal, jadeite: paintings of skeletons dancing, skeletons pursuing, skeletons scaring, skeletons reaping.

Beads, a pomander, lockets, a net-suke, an arm band, watches, daggers, stick pins, pendants, a gold spice box, a silver spice box, a dagger, a stirrup cup - all are shaped as leering, empty-eyed skulls or fleshless bones. They come from Mexico, India, Japan, Tibet, Italy, Germany, Scotland. Some are funny; some are sad. Some grotesque. Some exquistie.

It is not that after all these years of collecting such depictions of death that Kenneth Jay Lane is scared. For years he has kept them in his bedroom. He can contemplate his collection without shaking, shivering or becoming unduly morbid at the inevitable end of life. He does not close the door on the skulls before he turns off the light. He does not wake up in the night believing he hears something clanking.

On the other hand, he's auctioning them all off, every one, Thursday and Friday at Sotheby Parke Bernet in New York City.The bronze-hilted stiletto (the handle cast as a skeleton, the hands clasped over the rib cage, a snake entwined around the interior and the neck; the Vanitas portraits; the 18th-century German young man in a blue jacket and white waistcoat, half in the flesh, half out; the half head/half skull of a woman, one ornamented with flowers, the other with a snake; the woman in a brown, figured dress trimmed with lace, whose wig does not obscure the empty eye socket, the fleshless nose.

Why is he selling them? He is only in his mid-40s, not that old to be troubled by thoughts of death, though to some the first intimations of mortality come in mid-life. He says he is selling them "to give them back to the world." All objects, he reminds us, are "only borrowed for a time." He has no heir, nor great family home. A great one-collecor sale is a way of becoming an event in the history of art, a line in the provenance of the objects.

Sotheby estimated the sale will bring at least half a million dollars. But that was before the great interest in the collection became manifest. Already Sotheby has had to open the exhibit a week early. On opening day, the crowd of those who did not flinch to look death in the face curled like one of the snakes out the building and around the corner. So there may be more money. Perhaps a million.

But what will the vinter buy half so sweet as the stuff he sells? He won't say. "I hadn't thought about it. Perhaps put it in the bank." He and his English socialite wife, Nickie, were just divorced, the papers final a week or so ago. A divorce dinner, a parting reception, given by friends. All very civilized, of course. But she's gone back to England.

Lane made a reputation on inexpensive copies of expensive jewelry, especially those similar to David Webb designs. The story goes that rich women had both, and the burglars often took the Lane and left the Webb. Today, women don't wear as many precious stones, but he has other pots in the fire - he has designed shoes and other things, he invented a way of attaching rhinestones. He is a graduate of the Rhode Island School of Design. He worked once for Hattie Carnegie. He is good-lookking in a sleek, dark-haired, somewhat 1920s, Grand Hotel way, with a man-of-the world-charmm, a practiced suave manner.

He has always collected, he says, coins and stamps at first, junk too. "If you have two similar objects, you have the seeds of a collection. With three you are a collector." In another five years ago, he says, after a rest, he'll resume collecting. Collectors never stop, though they pause and change. Lane says that when he was in school, his mother game him a charge account at S.S. Pierce fancy food store. So he lived off liver pate, and used hhhis food money to collect objects.

In the Sotheby sale, roughly 200 out of 669 lots are memento mori. There are many other fine and lively pieces: a very rare and important German engraved crown of antlers from 1563, paintings, watercolors, drawings sculpture - Roman marbles from the first century, Greek heads from the second century - a collection of Egyptian amulets, a Madagascar wood ancestor figure, a Philippines wood head dress, a Baule or Guro wood face mask, a glittering Peruvian gold funerary mask, American Indian necklaces and pendants, a fine assortment of Indian miniatures and Buddhas, not to mention the Delft blue and white plates and the Staffordshire pearlware Satyr Mask.

Lane's house, the schatzkammer, the Ali Baba cave, the treasure house, is up for sale, too, with a price of $390,000 (mortgage of $44,951.80 at 8 per cent, yearly real estate taxes $14,687.640) by Sotheby Parke Bernet International Realty Corp. "I won't be getting my money out of it. I put far too much into the house. For the money, I could have lived these 10 years in the Waldorf." He hopes it won't go too soon, because his new place, only two floors instead of the present five, won't be ready until later. The new apartment sounds smashing with 20-foot high ceilings, very suitable in a Sanford White-designed 19th-century Beaux Arts building.

Lane's present townhouse is crammed, stuffed, decorated, embellished, ornamented, detailed, all with the master hand of the man of the world. The lot, in the Murray Hill section of New York on East 38th Street, is 17 by 96 feet, about the size of a Georgetown house, with a garden enclosed by a stone wall, inlaid with the blue and white Portuguese tiles, and with, of course, a fountain.

A guest comes in the front door, up a flight of steps and through an ornate entrance. The other day the door stood open while the moving men carted out priceless relics. The houseman was harried, but offered a cup of tea in the library/dining room on the lower floor, where at least the banquette matched the French fabric (covering the walls and ceiling like a tent) and might be presumed to remain with the house. Lane also is keeping his Boulle furniture and a few other "strong" objects for the high-ceilinged new flat.

When Lane greeted his guest, he had more chairs brought down so at least the tent room would not rattle. Two horn chairs by the fireplace (the mantle hand-painted to match the china) helped. He had a cup of tea as well, with orange marmalade instead of sugar and lemon. But every so often there were those crashes upstairs, and he'd race up to see if anything was lost. And there was the difficulty in extracting the picture lamp's cord from the acres of drapery covering the walls.

The conservatory at one end of the room still looked furnished, will all its lush green plants. This dinning room/library was used for lunch parties twice a week and dinners for 30-odd every six weeks for the 10 years he's lived in the house. The elegant, and practical, kitchen with its hanging space for pots and pans and the blue and white tiles and the barbecue fireplace is still intact.

The front hall, with its white and black marble floor and mirrored walls, a flying staircase and a tiger pouf, mourns the loss of the antlered head that once hung here. The drawing room retains its tortoise-shell-lacquered walls, the fireplace with the Louis XVI marble mantel, the glass wall and balcony. But the blackamoor head, the 76-inch-high portrait (by Albert Eeckhout) by an African chief, has been removed. The place is not the same. Still, there is that aura of elegance. It isn't difficult to believe it took him a year to decorate the house, once the home of writer Sophie Hill Underwood.

Like most collectors, he has brought and sold, betting his eye. There was a day when he had lunch with someone from Sotheby's and they said what about a great catalog sale of The Kenneth Jay Lane Collection - do it right, all at once. He liked the idea, and proceeded to do, for the catalog cover, a fascinating assemblage, almost a montage of objects atop a rug-covered table: a Vanitas painting, a beaten mask, a Greek statue, a book, three skulls, two crystal balls, and others, many others.

Why? Why collect memento mori? Why did he buy skulls, skeletons, mementos of mortality? His lawyer suggested a death wish but only because of the great costs. If he knows why he collected them, he won't say. He says his first of that genre was a skull made of pipe cleaners someone gave him. He says he likes natural objects that are symmetrical as is the skull. As a jewellery designer and manufacturer, he appreciates the exquisite craftsmanship in the tiny objets vertu. He quotes "eat, drink and be merry for tomorrow you die." But his reasons remain as mysterious as the objects themselves.

Why would anyone buy these grisly, though beautiful, memento? The death cult is very old. The Egyptians had their Book of the Dead, and their funerary objects. Medieval craftsman made skulls and skeletons for kings and emperors to remind them that though they were all powerful today, all men are mortal. Some say the reminders of death help to sweeten the reality of life, the skeleton at the feast.

Some of the objects are memorials to dear departeds, actually portraits of those gone before. Though the Lane collection does not include any, death masks, wax molds made from the face of corpses in coffins were very popular during Abraham Lincoln's last years. In Victorian times, memorial pictures made of hair, cut from some loved one's head, were often hung in the drawing room. In Memoriam pictures were popular around 1800, sometimes watercolors, more often made in silk needlework, depicting a cenotaph bearing an inscription to the lost one. Cemeteries in years past were full of stone likenesses of those, as the saying goes, who have been gathered.

In Mexico, the memento mori has a long history; for instance, in Lane's collection are the Aztec rock crystal skull mask, circa 1300-1500 AD, the amethystine quartz skull, circa 800-1200 AD. Today, you often see in Mexican bakery shops rock candy skulls or sweet rolls in the deathly forms. In some ways, it's like knocking on wood, a sign to fate that even in the midst of joy, we remember sorrow. Often the objects are inscribed with sayings on the subject: "Mors quam amara est memoria" - death how bitter it is to be reminded of you. "Feast today, famine tomorrow." And there was Li'l Abner's pig and pork chop: here today, gone tomorrow.

In medieval Christian churches memento mori were common enough, and the charnel houses of bleached bones were not unusual. Always, there is the other side of the coin, the anti-religions, based on death, not life. Black masses. Black candles and sickly sweet white flowers on the table, set for 13 for dinner. Last man clubs meeting every year until the last one dines alone.Ouija boards. Seances. The old dark religions remain. Halloween, as a memorial day, was once a major festival. Celebrated more vigorously in other parts of the world, it is still commemorated here, if only by the children.

In our century, death has been a forbidden word. But today, people are beginning to think again on the subject - courses in how to meet death, books on grief. Psychologists and philosophers say a period of mourning after the death of a dear one is necessary for people, a way of letting go, of accepting loss. And there are those who say we must all eventually come to accept our own eventual end.

Whatever the rationale, we all know, whether we welcome it or not, in the end, nothing is certain in life, except death.