GEOLOGY. 379 



nomena of the system would also shed sunilar light, or would their 

 testimony be as diverse as they are abeiTant? The recognized bodies 

 of this class include meteors, meteorites, and comets. While some of 

 these may be alien to the solar system, the common types were viewed 

 as merely aberrant manifestations of the same dynamic agencies as 

 those that gave rise to the normal members, the planets, planetoids, 

 planetesimals, satellites, and satellitesimals. To justify any treat- 

 ment at all on this basis, definite working concepts of the relations of 

 the aberrant to the normal members are required involving both 

 origin and active interrelationships. For this purpose, three mutually 

 consistent hypotheses were developed. In these, meteors, meteorites, 

 and comets were regarded as features of the same dynamic source and 

 import. The special cometic phenomena were thought to be due 

 mainly to the alternate passage of small, loosely organized bodies 

 through extremes of heat and cold, such as are found at the two ends of 

 their highly elliptical orbits. The main function assigned to these 

 extremes were deep cooling, shrinking, and riving, attended by the 

 absorption of gas material in the form of free molecules in the long outer 

 swing, while during the inner swing about the sun there was exfoliation 

 and trituration under its influence, accompanied by the discharge 

 and repulsion of the absorbed gas material, together Avith trituration 

 dust. The distinctive features of the comets, however, have little 

 bearing on the main subject of this inquiry and are left with this inade- 

 quate statement. Their dynamical features carry the main signifi- 

 cance, and these they share with the meteorites. In both cases the 

 orbital planes lie in all azimuths, the revolutions are retrograde as well 

 as forward, and the orbits are highly eccentric. The meteorites have 

 distinct peculiarities of organization, structure, and fragmentation 

 which, to justify the hypotheses offered, must spring naturally out of 

 the assigned conditions. The effort was to find phases of the genetic 

 and dynamic processes already assigned the normal features of the 

 solar system that would fit the aberrant members equally as well. 

 There was the more reason for this because of the growing conviction of 

 students of these seemingly erratic bodies that they are really members 

 of the solar system. 



1. The first hypothesis assumes tliat, previous to the genesis of the 

 present planetary system, the sun had secondaries of such an order as 

 could be developed by it without the cooperation of any other body, 

 i. e., distinctly small secondaries evolved on the same principles as 

 those that give rise to orbital ultra-atmospheres ; and tliat these small 

 bodies were thrown into irregular, highly elliptical orbits by the passing 

 body that cooperated in developing the present planetary system. 

 Such of these small bodies as were given very long elliptical orbits 

 experienced those extreme contrasts of conditions between their outer 

 and their inner courses to which cometic characteristics are assigned 



