Vol. 6, 1920 
PETROLOGY: G. P. MERRILL 
469 
the thin sections and has also been found to be the case in some of the forms 
freed from the matrix. They are plainly fragments of the encrusted forms 
and need no explanation. In no case, however, have I found a part glassy 
and porphyritic or holocrystalline structure developed in a polysomatic 
chondrule which does not suggest, from an examination of its external 
form, an origin as a rock fragment rather than a molten drop. 
That all the forms described cannot be attributable to a common origin, 
I consider self-evident, as already noted. The objections to an acceptance 
of the "fiery rain," or "fused drop" hypothesis in accounting for these 
last forms may be concisely stated as follows: 
(1) They are irregular in outline. 
(2) They never show the smooth, rind-like surfaces so characteristic 
of the enstatite kugels. 
(3) The outlines are not those of the original body from which they were 
derived, but for the most part plainly due to abrasion. 
(4) They show no gradations in crystallization from border to center. 
(5) They never show the peculiar surface depressions so characteristic 
of the enstatite radial and cryptocrystalline forms. 
(6) In brief, their present structural peculiarities, both external and 
internal are entirely inconsistent with any conceivable theory of origin 
but that of detrital particles from solidified magmas. 
It is perhaps questionable if such forms should be considered true chon- 
drules and perhaps the term pseudochondrule or chondroid had best 
be applied to them.^^ The true chondrules are those of the spherulitic 
or kugel type; others are rock fragments reduced to their present form 
through mechanical attrition. 
As bearing still further upon the question attention may be called to 
somewhat similar forms of known and artificial origin. In figures 11 to 
13, pi. 1, are chondrule-like forms found among the iron furnace slags 
at the Sparrow Point, Md., works of the Bethlehem Steel Co. Such are 
certainly strongly suggestive, in form, to meteoric chondrules though 
it is to be remarked that they are, interiorly, vesicular, almost pumiceous. 
Like forms I have found being blown from the Bessemer converters in 
the more energetic periods of operation. They formed true drops of "fiery 
rain." In figure 12 is shown one of these imbedded in the scoriaceous slag. 
Qualitative tests show these to consist largely of silica and oxides of iron, 
a little lime, and included minute flecks of metallic iron. 
In the above discussion, the fact has not been overlooked that very many 
of the glass and enstatite chondrules relegated above to the fiery rain 
hypothesis have likewise suffered abrasion through external agencies. 
This is plainly evident from the figures given and the multitude of frag- 
mental forms found in many chondritic stones. The encrusted form of 
