Glickman, 57, who has a Bachelor of Fine Arts degree from Syracuse University and is based in Hatfield, Pa., developed K'nex 10 years ago while he was working for the Rodon Group, his family's successful plastic-manufacturing business. They make it clear, as do Hoberman and Grey, that their toys are far from mere gizmos or gewgaws they're subtle learning tools and effective channels for creativity. Both Joel Glickman, the inventor of K'nex, and Jim Rothbarth, the creator of Chaos, describe their products with powerful metaphors. Like Zoob, K'nex and Chaos are sophisticated scions of classic construction toys. One of the easiest constructions you can make with Zoob, Grey is quick to point out, is a three-dimensional likeness of DNA's double helix. Fittingly, Grey likes to compare Zoob to the ultimate medium, DNA, the building block of life itself. ''Zoob really is its own medium,'' says Grey, who, like Hoberman, holds disparate degrees: a Bachelor of Science in genetics from the University of California at Berkeley and a Master of Fine Arts from Yale University. Artful Zoob constructions dangle from the ceiling like Alexander Calder mobiles and hang on the wall like Mark Rothko canvases. Primordial's offices are decorated with Zoob creations, ranging from a flamboyant lamp to a bumpy, armorlike dress.

Think of Legos on steroids, Tinkertoys on caffeine, Erector sets with an honorary degree from M.I.T., and you have a basic idea of what Zoob - an acronym of sorts for the disciplines of zoology, ontology, ontogeny and botany - represents. The most versatile of the new, sculptural, science-based toys is Zoob, a system of interlinking plastic pieces. And what is happening, hopefully, is that people are exposed to the pleasure of mathematics and geometry.'' I think what they see in these objects are relationships of a mathematical nature. ''They echo the movements of clouds, of fireworks.''ДЄs if his left brain has suddenly scrambled to keep up with his right, Hoberman adds: ''I always wonder what the folks who purchase our products discover. ''They expand, like we do as creatures,'' he says, describing his toys as a chorus of ambulance sirens wails outside the downtown Manhattan loft where he works. The design of the Unfolding Structure, Hoberman explains, can be applied to anything from easily retractable surgical instruments to gigantic stadium domes that dilate gracefully like the pupil of an eye - inventions he is currently developing. (Prices are suggested retail.) All are child-friendly versions of Hoberman's breakthrough engineering feat: the elegant, enigmatic Unfolding Structure. In the last three years, Hoberman's toy company, Hoberman Designs, has released the full-size ($45 to $55) and Mini editions of his sphere ($18 to $23), as well as a fold-up flying disk called the Pocket Flight Ring ($7). Their toys, which have the appeal of modern abstract sculpture, introduce children to complex mathematical and scientific concepts through the universal language of play. All have been developed by entrepreneurs like Hoberman, who share a passion for art and science. Their toys convey a 1990's sensibility, embodying the current buzzwords of ''innovation'' and ''interactivity.'' Relying on a child's own ingenuity rather than force-fed Hollywood or gender-specific imagery, they are as mysterious to the uninitiated as their names: Chaos, K'nex and Zoob, to name other leaders of the pack. Hoberman, who has a Bachelor of Fine Arts degree from Cooper Union and a master's degree in engineering from Columbia University, best represents a new breed of start-up toy makers specializing in colorful, versatile, tactile and refreshingly nondigital playthings. The world of toys is a place where people share whatever is neat and exciting to them.'' ''But it's been a revelation to see the huge variety of relationships that people have with toys. ''I didn't set out to make toys,'' says Hoberman, a lanky 42-year-old known in the play business as the erudite inventor of the Hoberman Sphere, a collapsible, skeletal ball made of brightly colored plastic. A curious hybrid of math professor and poet, Chuck Hoberman considers himself an accidental toy maker.

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