Clintonianum (Gray Herbarium)] CRESTED MARGINAL FERN Aspídium cristàtum X marginàle Both the crested fern and Clinton's fern appear to hybridize with the marginal shield fern with the result that the upper part of the frond is like marginale and the lower like cristàtum, including the veining and texture.

Still other species of ferns are known to hybridize more or less, as we saw in the case of Scott's spleenwort.

There are several varieties distinguished only by difference of color, lilac, red, yellow, orange, and white, which hybridize naturally, and may easily be obliged to do so artificially, if any particular shades are desired.

For of course both bees and butterflies stick on the whole to a single species at a time; or else the flowers would only get uselessly hybridized, instead of being impregnated with pollen from other plants of their own kind.