The more diversified in habits and structure the descendants of our car- nivorous animal became, the more places they would be enabled to oc- cupy. What applies to one animal will apply throughout all time to all ani- mals... So it will be with plants. It has been experimentally proved, that if a plot of ground be sown with several distinct genera of grasses, a greater number of plants and a greater weight of dry herbage can thus be raised. The same has been found to hold good when first one variety and then several mixed varieties of wheat have been sown on equal spaces of ground.
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