An Issue with Inheritance

[decimer]

I am doing some testing with inheritance, and I ran across this little bit of what I consider weirdness. Here is my class layout:

    class animal
    {

    }

    class dog : animal
    {
        public dog()
        {
            Console.WriteLine("woof!");
            this.bark();
            Console.ReadLine();
        }

        public void bark()
        {
            Console.WriteLine("woof! woof!");
        }
    }

I instantiate it like so:

animal dog = new dog();

Ok, so I noticed something a while back when instantiating an object with the type of the base class and making it a new instance of a derived class: the derived class's overrides and unique methods are not available to the new object. However, in this case, I am seeing that they are available through the derived class constructor. If I do this afterward:

dog.bark();

It doesn't work.

- Why is this?
- Is it useful in a way that I'm not seeing?
- Is there a way to access those methods again using that new object?