Nor is the question of the gelatinous condition of quartz so difficult, since Professor Graham has shown in his recent researches in dialysis that pure silica can be held in solution in water to the extent of 15 per cent.

Perhaps no finer proofs can be obtained of the quartz of granite having been gelatinous than in those specimens which contain schorl or tourmaline, so frequently found in Aberdeenshire. Fig. 5 is a good example of many such in my collection. and is singularly instructive.

It is well known to mineralogists that tourmaline crackles and splits with a small increment of temperature, and therefore could not have been present during a molten condition of the quartz; and that it was crystallised prior to the solidifying of the latter, is proved by the schorl impressing the quartz. Further, from many careful measurements of the peculiar fractures of the tourmaline and its contortions, and also from the amount of quartz which had entered into the fissures of the former, I am led to believe that the quartz, while in the process of crystallization, expanded 4th of its bulk. Such a force appears to me to be amply sufficient to cause all the upheavals and disruptions which other geologists have accounted for by supposing a molten condition of the primary rocks. If this view is correct, and if the highest peak is granite, and we know that the lowest is granite, it follows that, as the highest mountain is only part of the radius of the earth, a thick

ness of the crust of 168 miles is quite sufficient to yield expansive force to raise the highest peak of the Himalayan range. It may be objected, in regard to the temperature at which it seems the fluids were enclosed, as being too high for the normal temperature of the earth; but it must be recollected that pressure and also solidification from fluid conditions develop heat.

Organic Method in Zoology. By HUGH DOHERTY, M.D.

The gorilla, in its approximation to the "human form divine," has caused uneasiness, perhaps, to many consciences already more or less disturbed by the development theories of the

Origin of Species," which have been revived of late, with somewhat of a plausible appearance of natural truth being contrary to revealed religion. There cannot be a real discrepancy between natural and spiritual truth, although erroneous theories of natural organic laws may hold the mind in thraldom for a time and sow confusion in the consciences of pious men.

The so-called rationalistic theory of the "Origin of Species" nowhere proves the fact of any original metamorphic evolution by "natural selection;" but merely a development of individual organs and faculties by growth, exercise, experience, and education, from which facts it assumes the possibility, and even probability of metamorphic evolution in a genetic or creative sense. The assumption is entirely gratuitous, without the shadow of a demonstration.

If the theory were true, it would only prove that the original germs of animal creation were less perfect in powers of metamorphic evolution than the germs of procreation in the animal kingdom, and that the latter were, in fact, the continuation of the former, in a perpetual renewal of the first creation.

These questions need not be discussed, for nothing is known of the origin of species which deserves the name of a rational theory. Cuvier believed in the distinct creation of each species.

Man is evidently a part of the animal kingdom on our

globe, the highest type in the realm of vertebrata. He is the brain and mind of the collective animal kingdom, distinct from other types of organism, as the brain and nervous sysstem in the human body are distinct from other systems in the individual organism; and as man, having the highest cerebral development, is the highest organism in nature, so other species are inferior in degree, and correspond in rank with the inferior organs and systems of the individual organic unit.

All the higher vertebrata are more or less allied to man in general form and structure; and the monkeys are but little nearer to the human form than many other types of dumb creatures. Anthropoid apes are not less speechless than the common monkeys, nor are these less animal than other brutes in all their instincts and peculiarities. There is no more reason to suppose that man proceeds from apes than that apes proceed from dogs, and these again from lower types of vertebrata. It is mere hypothesis and wild conjecture. Organic method, duly understood, will scatter to the winds unsound hypotheses; but this is yet to be developed as a positive science.

The following outline of such a method may be, and no doubt is, imperfect; but it will serve at least to show the tendency of modern thought on these important questions, and preserve the minds of the unlearned from being disturbed by theories of natural science, which may be multiplied in various ways with an equal show of plausibility.

There is, no doubt, order and method in the universe, and in the plan of creation on our globe; and this plan is manifest in every variety of organism within the limits of investigation by the human mind.

Anatomy and physiology have already made the organs of the body and their special functions known to us in all minuteness, but the laws of organic unity are still a riddle without a satisfactory interpretation, We have not a comprehensive view of plan in the creation, nor a knowledge of the principles of natural organic method, either in the individual organism, or in the different collective units of organic forms, such as the vertebrata, articulata, mollusca, radiata, &c.

Organs, and groups of organs, in the body, have been well.

described, but series and systems have been hardly noticed. Individuals and congeneric groups of species have been well observed in different classes of the animal and vegetable kingdoms; but series and systems of congeneric groups have been less accurately studied by the eminent zoologists and botanists who have given their names respectively to many contradictory and unsatisfactory methods of systematic classification, and contending theories of the "origin of species."

Cuvier, De Blainville, Macleay, Van Der Hoeven, Owen, and many other eminent zoologists since Linnæus, have published each his own peculiar system of arrangement, based on what he deems some leading features of organic structure; but none of these agree in definite principles of method, or in the application of their views to natural divisions and associations.

Buffon, Geoffroy St Hilaire, and many other men of eminence in natural science, have theorised on the probable development and metamorphic evolution of all known species, including man himself, from a few simple germs of the lowest type and rank in nature. Cuvier and many other noble minds have denied the rationality of such a theory, and maintained the common faith of Christians with regard to the creation, The rules of method in division and classification are still in a chaotic state, even amongst those who are most eminent in science. Some lay stress on number as a key to natural divisions, others follow structural peculiarities without regard to theories of number. One of these views need not exclude the other; but as yet no leading principles of method have been universally recognised.

According to Mr Kirby, "the number five assumed by Macleay as a basis of method consecrated in nature, ought to yield to the number seven, which is consecrated both in nature and in Scripture." " Metaphysicians," he observes, "enumerate seven principal operations of the mind; musicians seven principal tones; and opticians seven primary colours. In Scripture, the abstract idea of this number is completeness, fulness, perfection." He believes that Mr Macleay's quinaries may be resolvable into septenaries by more elaborate investigations;" but we may here state that the number

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seven is not the only numerical basis of natural division in organic method.

Richard Owen makes four primary divisions in his classification of mammalia. His distinctions of the Lyencephalous, Lissencephalous, Gyrencephalous, and Archencephalous subclasses are, no doubt, known to all your readers, and therefore need no comment here. Many points of interest have been dwelt upon in these cerebral distinctions, but they do not form a complete system of divarication.

In lieu of the brain alone, or in connection with concomitant modifications of structure in other parts of the organism, we may take the whole body as a type of organic unity, and the most obvious natural divisions of the organism as a basis of numerical distinction and methodical grouping. These are the following distinct systems: the alimentary, the vascular, the generative, the nervous, the osseous, the muscular, and the cutaneous systems; with the organs of sense which belong to them respectively. In the vascular system, we include air-vessels, blood-vessels, and water-vessels, or the respiratory, the circulatory, and the urinatory series of organs in the body. The rank of each vertebrate mammalian organism may be seen in the cephalic structure, as remarked by Owen, but rank alone is not a sufficient basis of primary divisions in a natural organic method.

Taking this septenary view of the distinct systems, with the additional quinary view of the five senses, we have a natural numerical division of the complex unity exemplified in an individual vertebrate organism; and this principle of natural subdivision in a simple organic unity, suggests the idea of a similar numerical law of subdivision in the parts of a collective organic unity, such as that of the mammalian class of vertebrata. The collective ideal type may differ from the individual type in some minor points, such as those of a trunk in the elephant, a marsupium in the kangaroo, and other exceptional points of structure in certain species hardly shown, or.only rudimentally developed in the highest individual organism, such as that of man; but these details may be embodied in a general formula of method, including all the individual varieties of type and form.