[R] What's the meaning of "Species ~ ." in IRIS data

[Gundala Viswanath]

I am refering to a function call like this:

>data(iris)
>x <- svmlight(Species ~ ., data = iris)

I tried to see the content of it by typing:

> Species ~ .

but it gives nothing.  How can I see it's content ?

- P.Dubois