lead to their extinction? Do the simpler and lowlier forms always precede the higher and more complex; and does the introduction of any family in point of time harmonise with its place in the scale of organisation? Does the extinction of species appear to be, in every case, the result of a change in external conditions; or may not species, like individuals, have a term assigned to their existence from the beginning? If race after race follow each other in order of organisation, what countenance does this give to the theory of self-development? Is there, as far as palæontology can discover, any foundation whatever for the belief in a progressive transmutation of species, by which the lower gives birth to the higher; or does geology not rather establish the conviction of independent creations as time. rolled on and new conditions were prepared for their reception? Seeing that physical phenomena invariably take place under the orderly operations of natural laws, are we, in the spirit of sound philosophy, entitled to assume for vital phenomena any other mode of occurrence? In all other reasonings are we to adopt the inductive method, and in the solitary instance of LIFE-its incomings and outgoings-are we to forsake this course as impotent and unavailing, and appeal to the direct and miraculous interference of Creative Power? These, and numerous analogous questions, present themselves to the palæontologist; and if in human history chronologers are often disagreed as to times and incidents so recent as those that come within the range of a few thousand years, if ethnologists have failed to trace with certainty the relationship of the few varieties of our own race, and antiquarians be only beginning to decipher the phases of certain extinct civilisations, what marvel need it be that geologists are not yet as one as to events for which time has no dates, save "cycles" and "systems," or that they should be occasionally unable to discover the

nature and functions of creatures whose remains are so fragmentary, and to whom existing nature offers not a single specific identity? And yet, as we shall afterwards see, geological belief is much more uniform than is generally supposed; and, founding on this belief, palæontology has been enabled, within the brief space of half a century, to establish a history of the world's Past Life, more marvellous by far than the fabled creatures of romance, and yet so true that he who remains in ignorance of its facts can never hope to attain to a satisfactory knowledge of the scheme of life that at present surrounds us.

THE FAR PAST.

PALEOZOIC SYSTEMS-THE CAMBRIAN, SILURIAN, DEVONIAN, CARBONIFEROUS, AND PERMIAN.

ON glancing over the existing forms of the vegetable and animal kingdoms, struck as we may be at first by their wondrous variety and complexity, we gradually begin to detect innumerable affinities that link one family to another, and at length perceive that one plan and purpose runs throughout the whole. In like manner, when we turn to the still stranger and more complicated forms of the Past, and blend them with those of the Present―varied and endless as the details may appear-they gradually coalesce into one unbroken sequence of design, from the morning that first dawned on infant life, to the sunset that closed around us but a few hours ago. Without this uniformity in purpose and design, the study of nature would be impossible: we can only reason respecting the past from our knowledge of the present, and predict of the future from what is now taking place around us. And here at the outset we must specially guard against the misconception that in the Past Life of the globe we are to meet with anything that is monstrous or abnormal. As in the physical world we have no evidence of the operation of "aberrant" or "cataclysmal" or "revolutionary" forces, so in the vital world philosophy cannot point its finger to a single instance

of the abnormal. The "Antediluvian" and "Pre-Adamite monsters," of which we occasionally hear, are the mere creations of the platform orator, who would rather excite the marvellous for the chance of a little applause, than appeal to the reason of his audience by a simple statement of the truth as it occurs in nature. And yet, after all, the works of God are in themselves sufficiently wondrous to arrest the attention, and never more so than when arranged in that simplicity and perfection of design which it is the aim of legitimate science to detect, and the pride of the philosopher to explain.

In treating, then, of the Extinct Life of the globe, it shall be our aim to assimilate its forms, as far as the facts will permit, with those still living around us; to assign to them their places in the scale of being; to note their incomings and outgoings in point of time; and, above all, to discover their functions in the great economy of nature. Important as facts and specific distinctions are to the botanist and zoologist, the discovery of the functions and ultimate design of being is, to our apprehension, a more exalted pursuit; so true is it (in the impressive words of Coleridge) that "a man may be a chaos of facts, and yet lack the knowledge that God is a God of order." As the establishment of Law appears to be the highest effort of creative energy, so the expression of that law must ever constitute the noblest attainment of created intelligence. And this law is operating everywhere. The force that directs the drifting of a grain of sand is as fixed as that which guides. the revolution of a planet; the tiniest blade of grass that turns itself to the sun is but obeying the same law that regulates the growth of the lordliest oak; and the monad, invisible to the naked eye, is the creature of instincts and appetites as imperative as those that impel the actions of

man.

Nay, not a shower that falls, nor a breeze that blows