IN a celebrated lecture on &lsquo;Snakes,&rsquo; given by Mr. Ruskin at the London Institution in March 1880, he introduced his subject with the three considerations: &lsquo;What has been thought about them?&rsquo; &lsquo;What is truly known about them?&rsquo;&mdash;extremely little, as he suggested;&mdash;and, &lsquo;What is wisely asked about them, and what is desirable to know?&rsquo;<br />The three questions exactly agree with the object of my work, this chapter especially; and I will invite my readers to seek in their own minds the answer to the first question, which will also furnish a solution to the second, and, I trust, incite some interest in the third.