Why React.DOM is undefined?

Question

React 16.5.2
I am learning React by a book and try to use the factories of the "clear" React (i.e. not in JSX). I try to use one of React built factories but I get the problem:

(() => {    
    const my_h1 = React.DOM.h1(null,"Stuff") // TypeError: Cannot read property 'h1' of undefined
    ReactDOM.render(my_h1,document.getElementById('root'))
})()

Why does it happen?

UPD

This is the screen of the Learning React Functional Web Development with React and Redux book:

Answer 1

You have to make use of React.createElement to create an element instead of React.DOM

(() => {    
    const my_h1 = React.createElement('h1',null,"Stuff")
    ReactDOM.render(React.createElement(my_h1),document.getElementById('root'))
})()

Also with the latest version in React, React.DOM is no longet valid, you instead need to include the Dom-factories with this script

<script src="https://unpkg.com/[email protected]/index.js"></script>

Then everywhere replace React.DOM with ReactDOMFactories

e.g

ReactDOMFactories.h1(null, "Hello World!")

This change was introduced around version 15.6.0 in June 2017.