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ASTRONOMY: C. D. PERRINE 
capture. The general preference of the aphelia of these comets for the 
longitudes of the solar apex and antapex can scarcely be a relation 
other than to the sun's motion among the stars. The greater con- 
densation and preference for the longitude of the antapex appears to 
be real. Such a condition might perhaps follow if the cometary bodies 
were moving in general more rapidly than the Sun. 
To summarize, the short-period comets show a preference of their 
aphelia for the same ecliptic longitudes as do the asteroids, but radi- 
cally different from the distribution of the parabolic comets and those 
of very long period. As the short-period comets are conceded to be 
captures, has a similar preference of aphelia in the case of the asteroids 
also resulted from capture or is it due to some other cause? It is con- 
ceivable that such a preference might result from gravitational effects 
of the stellar system. If so why do the major planets show a different 
preference? The longitude of Jupiter's aphelion is at present approxi- 
mately 192°, sensibly that of the preferences of the minor planets and 
short-period comets. Is there any connection? The moderate eccen- 
tricity of Jupiter's present orbit does not tend to strengthen a belief 
in such a relation. 
It seems rather more than coincidence that the aphelia of all of the 
major planets are confined to one half of the sky and that the center of 
preference coincides so closely with the longitude of the sun's direction 
of motion in space, notwithstanding the observed revolutions of their 
lines of apsides, which differ greatly among themselves. Can it be that 
there are compensations or that our one or two centuries of (accurate) 
observations are insufficient to disclose gravitational or other effects of 
the stellar system? or does the mean of the planetary longitudes follow 
a changing direction of solar motion? 
It is perhaps possible to believe that the observed preference of the 
major planets is coincidence, but not so the preferences of the minor 
planets and the comets. They are too numerous and their preferences 
too consistent. These unquestionably indicate a common underlying 
cause. 
The parabolic comets show a very sharp maximum of aphelia at 
approximately 190° (fig. 4) preceding the one at 270° in some such 
way as the one at 20° precedes the strongest maximum of all at 90°. 
A division of the data into two groups shows the same peculiarities, 
indicating that it is real. This sharp maximum at 190° is perhaps 
significant, in connection with the similar preference of the minor 
planets and short-period comets for the same region. 
