W. E. B. Du Bois, the twentieth century’s leading black intellectual, once lived at 3059 Villa Avenue, in the Bronx. He moved to a small rented house there with his wife, Nina Gomer Du Bois, and their daughter, Yolande, in about 1912. When I’m walking in that borough I sometimes stop by the site. It’s just off Jerome Avenue, not far from the Bedford Park subway station. The anchor business at that intersection seems to be the Osvaldo #5 Barber Shop, which flies pennants advertising services for sending money to Africa and to Bangladesh. All kinds of people pass by. You hear Spanish and Chinese and maybe Hausa spoken on the street. The first time I went to Du Bois’s old address, I wondered if I might find a plaque, but the house is gone, and 3059 Villa is now part of a fenced-in parking lot. Maple and locust trees shade the front stoops, and residents wait at eight-twenty on Tuesday mornings to move their cars for the street-sweeping truck. A fire hydrant drips, slowly enlarging a hole in the sidewalk. Even unmemorialized, 3059 Villa is a not-unpleasant spot from which to contemplate the great man’s life.

About a forty-minute walk away is the Bronx Zoo. In 1912, it was called the New York Zoological Park, and it was run by a patrician named Madison Grant from an old New York family. Though he and Du Bois lived and worked within a few miles of each other for decades, I don’t know if the two ever met. As much as anyone on the planet, Grant was Du Bois’s natural enemy. Grant favored a certain type of white man over all other kinds of humans, on a graded scale of disapproval, and he reserved his vilest ill wishes and contempt for blacks.

As Du Bois would have remembered, in 1906 the zoo put an African man named Ota Benga on display in the primate cages. Ota Benga belonged to a tribe of Pygmies whom the Belgians had slaughtered in the Congo. A traveller had brought him to New York and to the zoo, where huge crowds came to stare and jeer. A group of black Baptist ministers went to the mayor and demanded that the travesty be stopped. The mayor’s office referred them to Grant, who put them off. He later said that it was important for the zoo not to give even the appearance of having yielded to the ministers’ demand. Eventually, Ota Benga was moved to the Howard Colored Orphan Asylum, in Brooklyn, and he ended up in Virginia, where he shot himself.

Madison Grant was someone who preferred to stay in the background and pull strings; but because of history, both past and present, he is not in the background anymore. Like other men of his social set—Teddy Roosevelt and Henry Fairfield Osborn, a president of the American Museum of Natural History, to name two—Grant adored nature, which to his milieu meant the North American continent, minus its original native population and reconstituted as a hunting preserve and contemplative retreat for themselves. Grant and others founded the conservation movement in America. They helped to save the buffalo. When the herds on the Great Plains had been almost destroyed, a new herd was started in Oklahoma, with animals shipped by rail from the zoo. Today, of the thousands of buffalo on the plains, many have distant relatives in the Bronx; the force behind the reintroduction was the American Bison Society, of which Grant was a principal member.

That was the “better” Grant. But, like a character in a comic book who harbors an inner arch-villain with a plan to destroy the universe, Grant had another side. Just as he feared that certain species of native wildlife would go extinct, he feared that the same would happen to a precious (and largely imaginary) kind of white person. To address this potential disaster, in 1916 he published what remains his best-known book, “The Passing of the Great Race; or, the Racial Basis of European History.” A centenary edition is available online.

To return for a moment to the “better” Grant: starting in 1906, he headed the commission that built the Bronx River Parkway. The commission bought up property along the river valley and created a landscaped autoroute leading to the headwaters in Westchester County. The project became a model for other parkways in the city and beyond.

In an oak grove overlooking the river is a flagpole with a plaque honoring “the founder of the Bronx River Parkway.” But the honoree is William White Niles, another commission member. There is no memorial devoted to Grant anywhere along the parkway; nor are there any public monuments to Grant at the zoo. In the borough where he did a lot for New York’s civic improvement, nothing is named for Madison Grant.

“The Passing of the Great Race” is probably why. It became one of the most famous racist books ever written, and today it’s considered part of a modern genre that began with Arthur de Gobineau’s “The Inequality of Human Races,” published in 1853-55. Hitler read “The Passing of the Great Race” in translation, admired what Grant had to say about the great “Nordic race,” and wrote the author a fan letter, calling the book “my Bible.” Grant took pride in the Nazis’ use of his book and sent them copies of a subsequent one, about how American Nordics like himself had conquered North America. He also was a director of the American Eugenics Society, thought “worthless” individuals should be sterilized, and considered his lobbying for the Johnson-Reed Immigration Act of 1924, which shut down most immigration to the U.S., to be one of the great achievements of his life.

The preposterousness of “The Passing of the Great Race” approaches the sublime. To summarize: according to Grant, all of Western civilization was created by a race of tall, blond, warlike people who ventured down from Northern Europe every so often to help start great cultures, such as ancient Egypt, Greece, and Rome, before retiring into their northern forests. Over time, a lot of these Nordics became “mongrelized” by mixing with “inferior races” (Grant’s books cannot be described without the use of many quotation marks), or else they killed one another off in internecine wars because of their bravery and their love of fighting, as they were doing at that very moment in the Great War. By Grant’s reckoning, the greatest men in Western history had been Nordics. Among the stars he claimed for the team, Leonardo da Vinci, Michelangelo, and Dante all clearly possessed Nordic blood, as he had determined by careful study of the shapes of their heads in busts.

He wrote that a major problem leading to Nordic “mongrelization” was the uncoöperative Nordic women, who had a habit of choosing the wrong men to mate with. Grant himself never married. He conceded, with regret, “It would be in a democracy, a virtual impossibility to limit by law the right to breed to a privileged and chosen few.”

And what was the special attribute the Nordics possessed that made them so unique and sacred? Grant didn’t talk about it much, but it slipped out once in a while. The secret dwelt in a mysterious substance known as “germ-plasm.” Everybody had it, but the Nordics’ germ-plasm was the best. Grant and his co-believers could apparently use phrases such as “our superior germ-plasm” with a straight face.