[Alexander von Humboldt was the] greatest scientific traveller who ever lived.

I fully subscribe to the judgement of those writers who maintain that of all the differences between man and the lower animal, the moral sense of conscience is by far the most important....It is the most noble of all the attributes of man.

When the views entertained in this volume on the origin of species, or when analogous views are generally admitted, we can dimly forsee that there will be a considerable revolution in natural history.

So great is the economy of nature, that most flowers which are fertilised by crepuscular or nocturnal insects emit their odour chiefly or exclusively in the evening.

Blushing is the most peculiar and the most human of all expressions. Monkeys redden from passion, but it would require an overwhelming amount of evidence to make us believe that any animal could blush.

Nevertheless so profound is our ignorance, and so high our presumption, that we marvel when we hear of the extinction of an organic being; and as we do not see the cause, we invoke cataclysms to desolate the world, or invent laws on the duration of the forms of life!

It may be conceit, but I believe the subject will interest the public, and I am sure that the views are original.