admissible in the lower sphere of Radiate life. It is consistent with facts that a quadripartite coral might bud out, or otherwise generate, a variety with a greater number of radiating laminæ. Some varieties, like those expressed by the modern generic terms Porites, Millepora, especially the M. complanata, with its strong vertical plates, were better adapted to bear the brunt of the breakers, and flourish in the surf, under the protection of the coating Nullipore. But to how small an exception is this relation applicable! Of the 120 kinds of coral enumerated by Ehrenberg in the Red Sea,* 100, at least, exist under the same conditions. The majority of species, originating in uncalled-for, unstimulated, unselected departures from parental structure, establish themselves and flourish independently of external influences. All classes of animals exemplify this independence: the Cetaceans, under an extraordinary and nicely graduated range of generic and specific modifications; and the same may be said of most Fishes.† So, being unable to accept the volitional hypothesis, or that of impulse from within, or the selective force exerted by outward circumstances, I deem an innate tendency to deviate from parental type, operating through periods of adequate duration, to be the most probable nature, or way of operation, of the secondary law, whereby species have been derived one from the other. It operates, and has operated, in the surface-zones where the chambered cephalopods floated, and at the depths where the brachiopods were anchored, as in the more defined theatre in which the various polyps of the coral reef display their diversities of color, size, shape, and structure, independently of outward influences. This tendency, moreover, is not exemplified in the ratio of the number, variety, or force of conceivable 'selective' surrounding influences, but is directly as the simplicity of the organism. In the Foraminifera, e. g., it is manifested in such degree that as many as fifteen genera defined by one given to― Intrigue with the specious chaos, and dispart Their points of contact and swift counterchange, have been found by his followers to be but varieties of a single type; and even this, too inconstant to come under the definition of a species given in p. 7. The departure from parental form, producing the beautiful varieties of perforate and imperforate Rhizopods, and which exemplify each group, respectively, under the Lagenine, Nummulinine, Globigerine, or * CCCXIX", p. 46. + XCIX', p. 44. under the Gromiine, Milioline, and Lituoline types, has effected its ends independently of inner volitions or of outer selections. Certain incrusting forms seem by the presence of siliceous spicula to have been derived from sponges; but no explanation presents itself for such transitional changes, save the fact of anomalous, monstrous births-as these varieties, and the whole assemblage of alternate-generative phenomena, would be called 'in high life.' According to my derivative hypothesis, a change takes place first in the structure of the animal, and this when sufficiently advanced, may lead to modifications of habits. But we have no evidence that the observed amount of change in Porifera, Foraminifera and Anthozoa, &c., has been attended with any change in the way or power in which they extract from their ambient medium, and precipitate, silex and carbonate of lime, or in the performance of any other vital function. As species rise in the scale, the concomitant change of structure can and does lead to change of habits. But species owe as little to the accidental concurrence of environing circumstances as Kosmos depends on a fortuitous concourse of atoms. A purposive route of development and change, of correlation and interdependence, manifesting intelligent Will, is as determinable in the succession of races as in the development and organization of the individual. Generations do not vary accidentally, in any and every direction; but in preordained, definite, and correlated courses. If the survey of a series of siliceous polycystins and diatoms, of zoophytes, of brachiopods, of ammonites, excites pleasure by their beauty, and raises worship of the Power manifesting itself in such inconceivable and exhaustless variety, I accept the relation as one designed, and in His due time, fulfilled : To doubt the fairness were to want an eye; 'Derivation' holds that every species changes, in time, by virtue of inherent tendencies thereto. 'Natural Selection" holds that no such change can take place without the influence of altered external circumstances educing or selecting such change. 'Derivation' sees among the effects of the innate tendency to change, irrespective of altered surrounding circumstances, a manifestation of creative power in the variety and beauty of the results and, in the ultimate forthcoming of a being susceptible of appreciating such beauty, evidence of the preordaining of such relation of power to the appreciation. Natural Selection' acknowledges that if ornament or beauty, in itself, should be a purpose in creation, it would be absolutely fatal to it as a hypothesis. 'Natural Selection' sees grandeur in the "view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one :" Derivation' sees, therein, a narrow invocation of a special miracle and an unworthy limitation of creative power, the grandeur of which is manifested daily, hourly, in calling into life many forms, by conversion of physical and chemical into vital modes of force, under as many diversified conditions of the requisite elements to be so combined. 'Natural Selection' leaves the subsequent origin and succession of species to the' fortuitous concurrence of outward conditions: Derivation' recognises a purpose in the defined and preordained course, due to innate capacity or power of change, by which nomogenously-created protozoa have risen to the higher forms of plants and animals. The hypothesis of derivation' rests upon conclusions from four great series of inductively established facts, together with a probable result of facts of a fifth class: the hypothesis of 'natural selection' totters on the extension of a conjectural condition, explanatory of extinction to the origination of species, inapplicable in that extension to the majority of organisms, and not known or observed to apply to the origin of any species. § 427. Epigenesis or Evolution ?-The derivative origin of species, then, being at present the most admissible one, and the retrospective survey of such species showing convergence, as time recedes, to more simplified or generalized organizations, analogous to von Baer's law of individual development, the result to which the suggested train of thought inevitably leads is very analogous in each instance. If to Kosmos or the mundane system has been allotted powers equivalent to the development of the several grades of life, may not the demonstrated series of conversions of force have also included that into the vital form? In the last century, physiologists were divided as to the principle guiding the work of organic development. The evolutionists' contended that the new being pre-existed in a complete state of formation needing only to be vivified by impregnation in order to commence the series of expansions, or disencasings, culminating in the independent individual. The 'epigenesists' held that both the germ and its subsequent organs were built up of juxtaposed molecules according * ccxш", Ed. 1860, p. 490. to the operation of a developmental force, or nisus formativus.' Haller maintained the principle of 'evolution,' Buffon that of 'epigenesis.' Hunter, who surpassed all his contemporaries in observations on the formation of the chick, thought he could see both principles at work, together with a third.' However, as he limited the 'pre-existing entities' to 'the materia vitæ universalis' and the absorbent faculty,' he would now be classed with the epigenesists.' For, he reckoned among the parts newly built up, not evolved, the brain and heart, with their appendages, the nerves and vessels, and so on of all the other parts of the body which we do not find at first.'* His third principle is merely a modification of epigenesis, viz: 'change in form and action of pre-existing parts.' 6 At the present day the question may seem hardly worth the paper on which it is referred to. Nevertheless, 'pre-existence of germs' and 'evolution' are logically inseparable from the idea of the origin of species by primary miraculously created individuals. Cuvier, therefore, maintained both, as firmly as did Haller. It is, perhaps, one of the most remarkable instances of the degree in which a favorite theory may render us blind to facts which are opposed to our prepossessions. Hunter's demonstrations of the epigenetic development of the blastoderm and initial parts of the chicks were not known to Cuvier; but the analogous ones of Wolff he had studied. To the phenomena of the blood-lakes and their union in order to constitute the 'circulus vasculosus' of the vitellicle, Cuvier opposes the following remark :-'Mais il faut nécessairement admettre qu'il y avait une pré-existence de quelques chemins pour les pointes rouges; car en virtue de quelle force la figure veineuse serait-elle toujours composée des mêmes vaisseaux ayant la même direction ? Comment ces vaisseaux aboutiraient-ils toujours au même point pour former un cœur ? Tous ces phénomènes ne sont intelligibles qu'autant qu'on admet quelque pré-existence.'T Haller, who had made some good observations on embryonal development, confessed that there was a stage in that of the chick in which the 'intestinal canal was not visible;' he would * xx, vol. v, p. xiv. + The encasement or imboxing (' emboitement ') of germs was deemed, a century or more ago, to receive support from the evolution of buds and other parts of plants, and from Swammerdam's discoveries in the chrysalis, not only of the parts which afterwards form the butterfly, as wings, antennæ, &c., but also of the eggs which were to be laid in that phase of life. Bonnet drew an inference in favor of the same view from his discovery of the numerous successive generations of Aphides which might be impregnated by a single copulation. (See, however, CXLII, pp. 27, 39) XXVIII". COCVI". § xx, vol. v, Pls. lxviii,-lxxviii. not admit, however, that it was not formed, or that it did not pre-exist; but affirmed that it was too minute to be perceived: not until the head and limb-buds of the chick appeared, was the intestine visibly evolved.'* To the beautiful demonstration of the steps in the successive building up and molding of the intestinal canal, out of the mucous layer' of the blastoderm, Cuvier objects :Mais quand il serait vrai que l'intestin se forme comme Wolff croyait l'avoir observé, il n'en résulterait aucune preuve en faveur de l'épigénèse; car le nombril, par lequel l'embryon tient à son placenta, est d'abord tout aussi large que l'animal luimême; c'est en enveloppant la portion du jaune qui doit rester dans l'intérieur, que la peau finit par rétrécir de plus en plus cette ouverture, qui primitivement n'en était pas une, et par la réduire à l'ombilic tel qu'on le voit dans le poulet ou dans l'enfant naissant.'t Geoffroy contended that the dogma of 'pre-existence of germs' owed its origin to a metaphysical explanation of illobserved phenomena. To admit that a germ included within itself all the forms, in miniature, which were afterward to be manifested, and to develop such theory by a matter so indefinable, was to multiply, at will, the most gratuitous suppositions.‡ His opponent's passages, above quoted, in defense of a doctrine now deemed by embryologists to be dead and buried, have hardly other than historical interest; and I should not have recalled them, or their subject, were it not that ghosts of 'preexistence' and 'evolution' still haunt some chambers of the physiological mansion, and even exercise, to many, perhaps an unsuspected sway over certain biological problems. Although in the Debates of 1830, the question of 'Preexistence of Germs,' was the sole one in which, as applied to Embryogeny, I held with Geoffroy Saint-Hilaire, I remained the thrall of that dogma in regard to the origin of single-celled organisms, whether in or out of body.§ Every result of formifaction I believed, with most physiologists, to be the genetic outcome of a pre-existing cell. The first was due to miraculous interposition and suspension of ordinary laws; it contained, potentially, all future possible cells. Cell-development exemplified evolution of pre-existing germs, the progeny of the primary cell. They propagated themselves by self-division, or by 'proliferation' of minute granules or atoms, which, when * "Partes animalis non noviter formantur, sed transeunt ex statu obscuro in conspicuum."-XXVIII", tom. viii, sectio 2da. p. 150-156. Also 'Mémoire II, sur la formation du Poulet,' p. 182. + cccvii", tom. iv, p. 277. § CCXLIX, CXLII. Anat. Philos., vol. ii, p. 280. |