229, J. J. H. TEALL—PETROLOGICAL NOTES ON 
opposite or shank end by an aggregation of globulites. In the 
Armathwaite longulites it appears probable that the growth has 
always been in one direction, that is from the end in contact with 
the augite granule. At first the conditions were such that an inti- 
mate union of the constituent elements took place, and the smooth 
rod-like portion was produced. After a time, however, the con- 
ditions became more and more unfavourable to the individualization 
of distinct substances. Larger globulites were produced and brought 
together by the action of the attractive forces; but these did not 
become perfectly united, and thus the rough portion of the longulite 
was formed. 
That the longulites are intimately connected with the globulites 
is proved by the occurrence of every possible kind of intermediate 
form. Thus one may pass from single globulites to a linear group- 
ing due to the coming together of two or more globulites without 
actual union, and from this, again, to an elongated form which has 
evidently been produced by the union of distinct globulites at their 
points of contact. These, again, may be connected with the more 
perfectly developed longulites by intermediate forms. As will 
naturally be anticipated from the facts already described, the spaces 
surrounding the longulites are free from globulites; the material of 
the globulites has been abstracted for the purpose of forming the 
longulites. What substance is it whose crystallizing force has led 
to the formation of these non-crystalline bodies? It is impossible 
to demonstrate the fact, but I have little doubt that it is augite. A 
suspicion of this is aroused when one notices that the longulites 
cluster round the augite grains, which they resemble in colour and 
general appearance, but not round the felspars; and this suspicion is 
confirmed when one studies carefully the structure of some of the 
least perfectly developed augites. These have sometimes a fibrous 
look, and occasionally run out into microlites which cannot be dis- 
tinguished from the longulites without the use of polarized light. 
I consider, therefore, that if we could isolate these globulites and 
longulites for separate analysis we should find them not to consist 
of pure augite substance, but of material richer in augite sub- 
stance than the surrounding glassy base; just as in Vogelsang’s 
experiments with sulphur and Canada balsam (Die Krystalliten, 
p- 8) the globulites and longulites consisted of Canada balsam 
containing more sulphur than the surrounding mass. 
As a rule, the felspars of the ground-mass are entirely free from 
globulites and longulites. It does sometimes happen, however, 
that a portion of the base gives the reaction of felspar under polar- 
ized light, and at the same time contains these bodies. 
We are thus led to the conclusion that the magma which re- 
mained fluid after the formation of the large felspars, the magnetite 
and many of the augite crystals and grains, still contained the 
chemical constituents of felspar and augite, and that the peculiar 
structures of the ground-mass owe their origin to the crystallizing 
power of these constituents acting under unfavourable circumstances. 
In short they may be regarded as the final attempts of these con- 
en 
