in the Radiates the germ forms around the yolk, as it were, by a sort of crystallization; in the Mollusks the whole of the yolk is changed into the substance of the embryo, whilst in Vertebrates a part is reserved to be used as food for it till a later period. Again, at first the embryo of a Salmon, for instance, is only a vertebrate animal in general; by degrees characters appear which successively distinguish it. Its transient states are the abiding condition of lower types; its cartilaginous backbone, for instance, resembles that of the adult sturgeon, as does its unequally forked tail, and its mouth placed underneath the snout. The Robin in the egg has been frequently observed by Professor Agassiz to have webbed feet. This parallelism of embryonic states with types lower in the scale may be extended indefinitely, and is highly important in a scientific classification. Some of the lower Mammals, the Marsupials, approach the inferior Vertebrates in bringing forth their young in a very undeveloped state, and bearing them about in a pouch, forming an intermediate step to the incubation of Birds, &c.

Connected with this subject is the remarkable phenomenon of alternate generation, which displays in the most interesting manner the want of individualization in the lowest types. In this, several stages elapse between the perfect animal and the appearance of the perfect young. The animal produces offspring not at all resembling itself, which in time produce the species of their parent, so that the immediate offspring do not resemble the parent, but this resemblance is found only when they again bring forth. In some cases several generations are interposed, and in some the second generation are mere living cases in which the true young are enclosed. For particulars on this most interesting matter we must refer to the work itself, only calling attention to the important principle illustrated by it. "It would seem (§ 351) that the individual life of the lower animals has not force enough to pass continuously, and, as it were, with one stride, through all the phases of its development.'

In the geographical distribution of animals we see also law and not accident. At the poles species are few, and a great uniformity prevails: "their forms are regular and their tints as dusky as the northern heavens." (§ 420) As we proceed southward variety of type, of form, color, &c., increase in parallel progression; the tropical types are the highest in each class. Each grand division of the globe has its peculiar

animals; their difference is not in proportion to the distance that separates them, but forms certain definite districts, called Fauna, within which the animals resemble each other, and which they do not overpass. These districts may be traced in the former ages of the earth corresponding to those now existing, for instance, in New Holland, which has a very remarkable and definite fauna, traceable also in its fossils.

Finally, if we take the geological succession of animals on the earth's surface, we find a remarkable coincidence between the historical succession of the strata and that of the animals inhabiting them. The most ancient fossiliferous rocks display the entire type of the Animal Kingdom in all four of its great divisions; all is there, as it were, in the germ. But the types by which they are represented are the lowest in each division, and very generally are to be found at present only in the embryonic forms of higher classes of the same type. For instance, the trilobites so common in the limestone of New York precisely resemble the embryonic forms of the crab and lobster. The paleozoic Echinoderms are principally Crinoids, whose form is an early or embryonic one of our present species, &c. There seems, however, to be not so much a weakness of animal life itself, as of direction. Thus the number of species is in many instances much greater than at present, but their organization is lower, their geographical distribution not so distinct, the different types not so definitely characterized, and their forms more irregular and fantastic.

Hence it is concluded" that there is a manifest progress in the succession of beings on the surface of the earth," consisting "in an increasing similarity to the living faunas, and among the Vertebrates, especially, in their increasing resemblance to Man." This connection "is to be sought in the view of the Creator himself, whose aim, in forming the earth, in allowing it to undergo the successive changes which Geology has pointed out, and in creating successively all the different types of animals which have passed away, was to introduce Man upon the surface of our globe."

We must remark that the connection of plan throughout the Animal Kingdom has been made more prominent in our resumé than it will be found in the work itself. Indeed, after the importance given to a purely scientific principle in Mr. Agassiz' lectures, we must confess ourselves somewhat disappointed not to find it penetrating the details somewhat more

than it does here. Perhaps it will be said that this would not be advisable for a work intended for beginners. But on the one hand, facts are much easier and better learned when we have a principle to string them on, and an interest is thus given to some who would not otherwise be attracted, — and on the other, if students are to learn by rote, they may as well and better learn principles than bare facts.

Considered as mere empirical Natural History the work before us has immense advantages over most similar ones in having been executed and superintended by thoroughly scientific men, and not by smatterers, as is generally the case.

In some passages we trace the marks of a foreign idiom, indicating that they were conceived in another language from that in which they are written: hence occasional obscurities; for example, p. 107" Wheat taken from the catacombs of Egypt has been made to sprout and grow in some well-authenticated cases.' Page 73, Life is made to consist in the equilibrium of nourishment and waste-the opposite of the truth. Death, and not Life, being equilibrium. What is meant is antagonism. Some expressions are too technical: e. g., p. 169, familiar animals will not be recognized under the names of Limulus and Bassaris; p. 171," paved teeth" would not be intelligible to the beginner;-p. 16, Incessores is translated "Birds of Prey";-p. 135, instead of groups of individuals, should stand parts, &c. There are some uncertainties of orthography, &c., e. g., polypi and polyps ; and the commas might be somewhat reformed in another edition. The work has, we believe, been somewhat delayed, and therefore probably hurried at the close. Prefaces in this way are apt to show marks of haste, as one of which we presume the very slight mention of Mr. E. Desor must be considered, as, if we are rightly informed, the elaboration of a large part of the work is due to him. This is doubtless owing merely to want of consideration of the force of phrases in this comparatively unimportant part of the work.

ART. IV. CONSTITUTIONALITY OF SLAVERY.

Or the great questions which are now agitating the community not one deserves a more careful and earnest investigation, not one involves higher considerations of duty than this: Does the Constitution of the United States, when rightly interpreted, support Slavery? We propose to consider the question as briefly as is consistent with clearness.

Of course only that slavery which is legal can be constitutional. But it is argued that all slavery is illegal. Law is defined to be a "natural, permanent, unalterable principle; any rule," it is said, "not existing in the nature of things, or that is not permanent, universal, and inflexible in its application, is no law." The civil rights of men, it is contended, are defined by the "immutable and overruling principle of natural justice."

Justice must be either absolute or relative. An absolutely just act is just at all times, in all places, and under all circumstances. A relatively just action is just only at some particular time and place, and under some particular circumstances. Consequently, the rule of relative justice is constantly changing with time, place, and circumstances. Therefore it cannot be unalterable. On this theory, therefore, it cannot be law, because law is unalterable. Law, on this theory, then, must be synonymous with absolute justice. Without denying that it is possible for the human race ultimately to acquire a knowledge of the test of that which is absolutely just and right, it is sufficient for the purposes of our argument that it is evident that no such test at present exists. But if law is synonymous with absolute justice, if we cannot tell what is absolute justice we cannot tell what is law; and, consequently, cannot prove even slave-holding to be unlawful. But law is a practical science. To remain so, we cannot take our notions

*It seems unnecessary to argue this point. The author of this theory, strangely enough, admits the present non-existence of a test of what is naturally just. He says, "whenever the natural law is sufficiently certain to all men's minds to justify its being enacted, it is sufficiently certain to need no enactment. On the other hand, until it be thus certain, there is danger of doing injustice by enacting it; it should, therefore, be left open to be discussed by any body who may be disposed to question it, and to be judged of by the proper (?) tribunal, the judiciary." He therefore admits that in some cases we cannot now tell what natural justice demands of us. But if we had a test of natural justice we could decide all cases now.

of relative justice as its test, and declare not to be law every rule which we believe to be unjust; because if we do this law will necessarily be constantly changing, like our notions of relative justice, with time, place, and circumstances, and it needs no argument to show that a law which is thus constantly changing, with whatever name we may please to dignify it, is only another word for despotism. We would not, however, be misunderstood. Every legislator should endeavour to make the laws carry out the highest present idea of justice. But if, as has always hitherto been the case, every legislator fails in the attempt, the laws are none the less laws although they prescribe a rule at variance with the requirement of relative justice.

This fundamental objection being disposed of, we proceed to state briefly the law of England specially bearing upon the question before us.

The common law of England (1 Black. Comm., 67,) “is properly distinguishable into three kinds. 1. General customs; which are the universal rule of the whole kingdom, and form the common law, in its stricter and more usual signification. 2. Particular customs; which for the most part affect only the inhabitants of particular districts. 3. Certain particular laws," (the civil and canon law) "which by custom are adopted and used by some particular courts."

The existence and validity of general customs are determined by the courts. To be valid a general custom must have existed beyond the memory of man. In England this time of legal memory extends back to the commencement of the reign of Richard I. (1189.) The existence of a particular custom is proved as a question of fact, unless the court recognizes its existence. To make it valid certain things are required. Among these it is necessary that it should have existed beyond the memory of man Thus, to establish a title by prescription to an easement, a man must be able to show that he and those under whom he claims have immemorially used to enjoy it.

The remark," Law is a progressive science," was frequently made by the late Judge Story. It is eminently true of the common law, for it is not true that the common law has existed ever since the close of the twelfth century. Many exceedingly important portions of it, as the English law of the Road, (1 Ib., p. 74, note,) the presumption of a lost grant from twenty years adverse possession of an easement, very promi