Rethrowing exceptions

Why doesn't the following doesn't handle the exception that was rethrown? I tried all the combinations but none of them would show the output in last catch so I'm confused!

Derived D;

try {
       throw D;
} catch ( const Derived &d) {
       throw;
} catch (const Base &b) {
      cout << "caught!" << endl;
}

Derived D;

try {
    throw D;
} catch ( const Derived d) {
    throw;
} catch (const Base b) {
    cout << "caught!" << endl;
}

Derived D;

try {
    throw D;
} catch ( const Derived d) {
    throw;
} catch (const Base &b) {
    cout << "caught!" << endl;
}

Derived D;

try {
    throw D;
} catch ( const Derived &d) {
    throw;
} catch (const Base b) {
    cout << "caught!" << endl;
}