406 Mr. H.G. Seeley on the Laws which have determined 
forms, discharging rock-matter into the sea; while the settling- 
down of these materials upon the sea-bottom is the work deter- 
mined by gravity. The motion of matter around the land is 
for the most part due to the tide-generating power of the sun 
and moon; but the arrangement of this matter on the sea- 
bottom is due to gravity. 
3. The motion of living things on land is due primarily to 
the sun’s heat distributing the individual species in zones of 
uniform temperature, modified by movements in the earth’s 
crust producing distribution irrespective of temperature. The 
distribution of living things in water is due primarily to move- 
ments in the earth’s crust, modified subsequently by the form 
of coasts, the abundance of life, and by temperature. 
4. On the hypothesis of the earth having cooled from a fiery 
state, the surface-rocks would be uncrystalline granitoid sub- 
stances, the denudation of which would furnish clays. But, as 
a matter of fact, everywhere beneath stratified formations some 
rock of a granitic character is found. Therefore, assuming all 
stratified rocks to he derived from the denudation of plutonic 
rocks, it is necessary to consider what stratified deposits such 
denudation can result in. : 
5. If the plutonic rock is crystalline, a granite may be taken 
as the type. It consists of quartz, felspar, and mica—speaking 
roughly, in the proportions of 25 per cent. of quartz, 55 per 
cent. of felspar, and 20 per cent. of mica. The quartz is heavy, 
and washes out in grains, which, left behind, form a deposit of 
sand. Hence, if granite were the only source of water-formed 
rocks, and only denuded by the sea, one-quarter of all known 
stratified rocks would be sands and sandstones. And therefore 
the quartz-grains (the sandstone to be, or that is) will form a 
belt near to and around the shore, and will always be indubit- 
able evidence of near vicinity to land. And supposing the mica 
not to be decomposed, from its fine flaky character it will, 
according to circumstances of slope of sea-bottom, currents, &c., 
be carried either to the limit of the sand, and go to form a 
micaceous sandstone, or go beyond the limit of the sand, and 
form a micaceous clay (slate). 
The felspar readily decomposes into a clay, setting free in 
addition a quantity of silica and potash or soda; and, from the 
extreme fineness of its particles, this clay is carried out to sea 
further than the sand, and surrounds the land as an outer belt, 
at least twice as broad as the sand-belt. 
But if the denudation takes place on the land-surface by the 
agency of rain and running water, the major part of the sand » 
will be left behind; and the detritus poured into the sea by the 
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