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by which its varieties are differentiated and endeavor to find out how the features peculiar to it have originated. He may then be able logically to connect it with very distant relatives.

Now to turn to the collateral evidence. Collateral evidence on distribution and relationship is furnished by paleontology. Such data are really direct and important when fossil remains occur in sufficient quantities, but this is not often the case. It is usually fragmentary and can be classed with that of archeology. Neither archeology nor history furnishes certain proof of plant origin, however, as we shall see. Their evidence must simply be given the weight it deserves when considered with other facts. Lastly, philology furnishes indications as to the history of a species, for common names of cultivated plants are well preserved in the languages of the people who have used them. But, like other evidence, it must be accepted with caution. The cashew is called by the French pomme de Mahogani, which is all right except that it is not an apple and has nothing to do with mahogany. This shows how much worse a compound name is than a simple name, since with a simple name there can be but one error.

We shall endeavor to construct our history and evolution of maize along these lines, though not keeping the same order.

Maize has not been found in the wild state, although it is such a remarkable plant it seems improbable that with our present knowledge of plant distribution it should remain undiscovered if in existence. This fact has made the problem of its nativity very difficult, even though Americans have been satisfied of its new-world origin for some time. Competent critics have skillfully argued old-world origin, and from the strictly historical point of view there was earlier much to be