462 
PETROLOGY: G. P. MERRILL 
Proc. N. a. S. 
Brezina, to whom is so largely due the building up of the magnificient 
collection at Vienna, concludes a review"^^ of the subject with the statement, 
"Durch die vorangefuhrten Beobachtungen konnen wohl die alteren Aus- 
schauugsweisen als beseigtig betrachteh werden, und wir konnen wohl 
mit Bestimmtheit die Meteoriten als gestorge iiber hastete Krystallbild- 
ungen in einem einzigen gemengten magma bezeichen." This I under- 
stand includes both the ground mass and its chondrules. 
Hussak, basing an opinion on experimental work by himself and Dolter^^ 
suggests that chondritic meteorites, like that of Uberaba, Brazil (a crys- 
talline chondrite), originate through the long continued immersion of 
meteoric stones in a nickel-iron-rich magma, and are to be regarded as 
true volcanic ejectamenta, "Ich mochte demnach die Meteorsteine durch 
ultrabasische Eruptivgesteine vergleichen und die Bildung der Chondren 
wie der Triimmerstrutur und der schwarzen Adern als eine magmatische 
Eirnwirkung vor der Ejektion ansehen. Daher die vollstandigen Uber- 
gange in Siderite und die Deutlichen Korrosionserscheinungen an den 
grossen Olivinkristallen der Pallasite." 
C. Klein, in 1906,^^ evidently basing an opinion largely on figures of 
chondrules in the works of Hahn and Tschermak, affirmed that 
there occur many ideally perfect forms that lack the eccentric radiating 
structure, but are "radial strahlig," from a centre, equally in all directions 
and are true spherulites. Those not having this perfection of structure 
are considered fragments. It may be well to note before going further, 
that Klein apparently stands alone in holding these views though they 
may be correct for certain forms. 
WahP"^ would explain the formation of the chondrule as due to the cool- 
ing of a silicate melt in a heated atmosphere, the resultant drop crystal- 
lizing from the surface inward. "Die Entstehung der Chondren lasst 
sich also ganz allemein als durch Zerstaubung von Silikatschmelz fluss 
innerhalb einer heissen Atmosphare und Kristallization der hierdurch 
enstandenen Tropfen von aussen nach innen zu erklaren." This again 
would seem to refer only to the cryptocrystalline, radiating enstatite, and 
the barred and monosomatic olivine chondrules. 
Finally, in 1913, Fermor,^^ of the Indian Survey, suggested that the 
chondrules are remelted garnets. 
In my preliminary considerations of this subject, I felt that in order to 
arrive at a solution of the problem it would be necessary to begin with a 
study of the crystalline chondrites, since in case the chondrules were 
spherulites, it would be here that they would be found in their primary 
condition of development. A study of all the thin sections of stones be- 
longing to this group, now in the Museum collections has, however, brought 
about a change of view since in none of them do I find chondrules developed 
in the variety and perfection of forms existing in those meteorites which 
are plainly tuffaceous. This fact and others to be mentioned later have 
