CHAPTER XX. CLIMATIC AND INDUSTRIAL ADAPTATION. The surface of the earth is naturally divided into zones or centres of existence. These great centres of creation have each their _Fauna_ and _Flora_, their animal and vegetable life peculiar to themselves alone. Geographical writers use these terms, and speak of the temperate, frigid, and torrid zones, etc., as mere designations of certain portions of the earth where the climate is widely varied; but this is very subordinate to the real differences that separate the great centres of organic life. All creatures, indeed all organic and living things, have their centres of existence, their local habitations, their places in the mighty programme of creation. They are all adapted to these great centres of life—their organic structure, their faculties, and the purposes they were designed to fulfil, all harmonizing with their localities, the positions the Almighty has assigned to them. There are approximating forms of life, certain genera among animals and plants, that may be said to belong to the same family or group, but which are found in different zones or centres of existence, but there is no such thing as the same _species_ being found in more than one centre of creation. All the animals and plants of Europe are, therefore, different from those of America, as all the creatures that belong to the northern region of this continent are specifically different from those of the tropics.