Deuteronilus, [259-261].
Development of canals, latitudinal law of, [299], [302], [375];
follows melting of polar caps, [302], [338-340];
Devonian era of the earth, [141].
Diaphragm, the great, [265].
Diplopia, [196].
Djihoun, narrowest double, [228-230];
embouchure of, [219-220];