Precious cargoes

Diane and I are back in Cambridge, Mass., after a longish exile, and what we've noticed right away is the boom in baby transportation. The proprietor of the Cambridge Cycle Mart, which specializes in Biemme strollers from Italy, tells me business has never been better. ''They come all the mothers to buy,'' he says, in the pithy vernacular his customers cherish. ''And when the wheels go broken, I fix.''

But it is not just the eight-wheel strollers and fancy carriages that have caught our eye; it's all the makeshift contraptions - the pouches, harnesses, knapsacks, backpacks, and bicycle thrones - in which parents now transport their squirmy hopefuls. One senses these are more than mere conveyances. Fashioned out of love and necessity, they carry the next generation into the very center of our world's time and space. It must be quite an education for the babies.

The other day an infant and his father glided past our window, the father pedaling resolutely, the baby squinting in the opposite direction, at its recent past. Strapped and wrapped in a chair atop the wheel, it looked, in Dickens's words, ''as secret and self-contained and solitary as an oyster.''

On the whole, I am cheered by such sights, if only because they bespeak an end to the narcissistic seventies, when youth appeared to behave solely in the present tense, and when faith in a future beyond one's self seemed sharply circumscribed. That relatively fruitless cohort of young Americans at times reminded me of the protagonist in Machado de Assis's bitter novel, ''Epitaph of a Small Winner,'' who, speaking to us from the grave, explained he was a small winner because ''at least I left no progeny.'' Can there be a more powerful metaphor for despair than intentional barrenness?

Cambridge's babies, of course, are not the first hereabouts to be cheerfully borne. Long before the Stork Time Maternity Shop on Church Street got the idea to sell corduroy ''Snuglis,'' replete with zippers, Narragansett Indian mothers were lugging their papooses in similar pouches. (''Papoose,'' a Narragansett word, is not to be confused with the Greek ''pappus,'' though the words seem uncannily linked, ''pappus'' meaning an appendage that crowns fruit in various seed plants.)

Nearly all American tribes, in fact, used baby-carrying contrivances, a circumstance that must have done wonders for the infants' sense of tribal acceptance. For if kids are eventually to enjoy full membership in the club we call society, they have to begin by glimpsing more of the world than four walls and a baby sitter.

The papooses around here get an early induction into society without suffering the inconvenience of being separated from their parents. Wherever the parents go, the babies come along - not only for the ride, but also for the enlightenment. Every outing is an eye-opener.

Parents, I have noticed, promote the process by conversing with their small passengers. Recently I overheard a father and his Snuglied tot as they paused in front of a bookstore window.

''Look,'' said the father. ''They have a complete set of Toynbee.''

''Frrrmmingel,'' the baby answered wetly.

Such reassuring conversations may ultimately have a more beneficent effect on civilization than all the talents our leaders can bring to bear. Those precious cargoes being toted around Harvard Square will soon be walking among us with a confidence and a capacity for affection born of early perambulation and frequent snuggling. It is true that what we get ''out of the cradle endlessly rocking'' is precisely what we put into it. This time, perhaps, we will get love.