upcasting in vector

Hello, I have the following code.

#include <vector>
#include <iostream>

class Foo {
public:
  Foo(){}
  virtual void print() const { std::cout << "foo" << std::endl;}
};

class Boo:public Foo {
public:
  Boo():Foo(){}
  virtual void print() const { std::cout << "boo" << std::endl;}
};

int main(void) {
  std::vector< Foo > vec;
  Foo ff;
  Boo bb;
  vec.push_back(ff);
  vec.push_back(bb);
  std::vector< Foo >::iterator Ivec = vec.begin();
  while(Ivec != vec.end()){
    (*Ivec++).print();
  }
  std::cout << "===========" << std::endl;
  std::vector< Foo* > vec2;
  vec2.push_back(&ff);
  vec2.push_back(&bb);
  std::vector< Foo* >::iterator Ivec2 = vec2.begin();
  while(Ivec2 != vec2.end()){
    (*Ivec2++)->print();
  }
    return 0;
};

the output is:

foo
foo
===========
foo
boo

so when I create a vector of pointers to Foo, the upcasting of print()
works fine, but it does not for a vector of Foo.

Could you, please, tell me what am I missing here?

Thank you very much for help and your time

m