Page:The Science of History and the Hope of Mankind.djvu/27



the habits of life and habitats, movements of limbs and other organs, as well as the methods of reproduction and rearing, are all influenced by and adapted to the varying conditions of the environment. The plants and animals of land as well as water have different modes of life and forms of body adapted to their different abodes and surroundings. Terrestrial plants and animals, again, display diversity of structure and characteristics owing to the variety of sets of favourable and unfavourable circumstances amidst which they are placed.

The maintenance of life as well as the propagation of the species, also, do not depend solely on the individual life of the organism. In fact, every aspect of its life is influenced by the whole environment surrounding it.