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ASTRONOMY: C. D. PERRINE 
of eccentricity for relative mass: (a) the preference may be of larger 
eccentricities for systems with the smaller relative masses for the 
secondaries, or it may (b) be the reverse, a preference of the larger 
eccentricities for the systems with the larger relative masses for the 
secondaries. 
The first of these possibiHties is the one of which such widely dis- 
tributed evidence has been found. Such a condition appears to result 
naturally from capture. 
The second possibility (b), on the other hand, could not result from 
capture, nor does evidence of such a condition appear to prevail in 
nature. 
It cannot but be regarded as significant, therefore, that of three 
possibilities the one which is actually found to prevail in nature is the 
one which would result directly from capture. The evidence is not suf- 
ficient to establish from the observed preference the reverse reasoning, 
viz., that because of this observed preference it must be concluded 
that binary and planetary systems have resulted from capture. . It 
must be admitted, however, that this observational evidence, which 
appears to be stronger than any as yet adduced for a process of fission, 
places a theory of capture in a new hght, and requires that it be 
seriously considered, not only for the solar system but for stellar 
systems as well. 
If the secondary bodies of the solar system have been captured, 
and providing no force has seriously disturbed the major axes of their 
orbits since, or disturbed them all equally, we might expect to find 
a preference of the directions of their aphelia for some particular region 
of sky. It does not necessarily follow that it would be the region of the 
apex of solar motion. Differences of direction or velocity in the rela- 
tive motions of the sun and the secondary bodies previous to capture 
could conceivably cause an apparent preference of their aphelia for 
almost any part of the sky. 
The following four diagrams give in condensed form the results of 
an examination of the aphelia of the 8 major planets, 821 minor planets, 
45 comets with periods of less than 80 years and 364 comets with longer 
periods and essentially parabolic orbits. 
It is impossible to give in a limited space a full summary of the con- 
siderations resulting from this examination which has included not 
only the directions of apheha but the orbital inclinations, longitudes 
of the nodes, galactic relations, etc. A full account of the investigation 
will be published in another place. 
