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The Evolution of the Solar System . [May, 
Of course, in such a process, other conditions than those 
here considered might arise. In vast regions of the nebula 
it is possible that no single mass might aggregate sufficiently 
large for its energy to overpower the resistance of its neigh- 
bours. In such a case the minor masses might preserve 
their individuality, and continue to revolve as separate 
planets around the centre. But such a condition could arise 
only under special relations between the Sun and its attendant 
planets ; and these relations exist in one portion of our 
Solar System, in the region of the asteroids. The huge 
mass of Jupiter has swept the space beyond these of all its 
minor planets. But the influence of its perturbing attraction 
is constantly exerted against the counter influence of the 
Sun, and at a certain distance inward the solar attraction 
must have hindered perturbations sufficiently wide to bring 
the minor planets within the grasp of Jupiter. For a vast 
space inward from this limit the quantity of matter seems 
to have been comparatively small. The next inner planet is 
Mars, one of the smallest of these bodies, and quite inca- 
pable of greatly perturbing, or of drawing to itself masses 
at the distance of the asteroids. In this ring of asteroids, 
then, and in their great diversity of orbits, we seem to per- 
ceive a permanent remnant of a temporary condition of the 
Solar System, ere the overmastering attraction of the larger 
masses had denuded the space in their vicinity of all similar 
minor planets. 
It is by no means impossible that cometary masses arose 
from the same causes. Small bodies, whose orbital revolu- 
tion was greatly disturbed by the perturbing attraction of 
the large masses, and which yet succeeded in escaping from 
this influence, might well have gained very elliptical orbits 
through these vigorous lateral attractions, and been forced 
to assume the most diversified directions of revolution 
around the centre. 
The final direction of revolution of the planetary masses 
would necessarily be the complement of the many motive 
influences which arose from their mode of aggregation and 
the various perturbations to which they were subjected, their 
orbits thus becoming necessarily more or less elliptical, and 
inclined to the Ecliptic. 
Again, as Nature knows no great or small, and as her 
principles of operation constantly work to the same result in 
the same general conditions, without reference to the quan- 
tity of matter concerned, so we may reasonably look for 
similar results to arise during the condensation of the 
planets. These were probably at first gaseous in aggregation, 
