Now shall we infer that the compact, closely coiled Ammonites of the Jurassic deposits, while continuing their own kind, brought forth a variety of other kinds, and so distributed these new organic elements as to produce a large number of distinct genera and species? I confess that these ideas are so contrary to all I have learned from Nature in the course of a long life that I should be forced to renounce completely the results of my studies in Embryology and Palaeontology before I could adopt these new views of the origin of species. And while the distinguished originator of this theory is entitled to our highest respect for his scientific researches, yet it should not be forgotten that the most conclusive evidence brought forward by him and his adherents is of a negative character, drawn from a science in which they do not pretend to have made personal investigations, that of Geology, while the proofs they offer us from their own departments of science, those of Zooelogy and Botany, are derived from observations, still very incomplete, upon domesticated animals and cultivated plants, which can never be made a test of the origin of wild species.[11] [Footnote 11: The advocates of the development-theory allude to the metamorphosis of animals and plants as supporting their view of a change of one species into another. They compare the passage of a common leaf into the calyx or crown-leaves in plants, or that of a larva into a perfect insect, to the passage of one species into another. The only objection to this argument seems to be, that, whereas Nature daily presents us myriads of examples of the one set of phenomena, showing it to be a norm, not a single instance of the other has ever been known to occur either in the animal or in the vegetable kingdom.] In my next article I shall show the relation between the Cretaceous and Tertiary epochs, and see whether there is any reason to believe that the gigantic Mammalia of more modern times were derived from the Reptiles of the Secondary age. * * * * * THE WHITE-THROATED SPARROW. Hark! 't is our Northern Nightingale that sings In far-off, leafy cloisters, dark and cool, Flinging his flute-notes bounding from the skies! Thou wild musician of the mountain-streams, Most tuneful minstrel of the forest-choirs, Bird of all grace and harmony of soul, Unseen, we hail thee for thy blissful voice! Up in yon tremulous mist where morning wakes Illimitable shadows from their dark abodes, Or in this woodland glade tumultuous grown With all the murmurous language of the trees, No blither presence fills the vocal space. The wandering rivulets dancing through the grass, The gambols, low or loud, of insect-life, The cheerful call of cattle in the vales, Sweet natural sounds of the contented hours,-- All seem less jubilant when thy song begins.