542 PROFESSOR JAMESON'S NOTES ON 
the rock a conglomerated aspect. In some of these contem- 
poraneous masses the structure is simply granular, in others 
it IS granular and slaty, and these latter in particular have 
much the appearance of broken masses; and phenomena of a 
similar kind, in other parts of Scotland, have been described 
as fragments contained in granite. These pseudo-fragments 
are sometimes intermixed with the syenite at their line of 
junction with it ; in other instances, they gradually pass into 
the bounding rock ; and occasionally veins or inequalities 
of the one shoot into the mass or body of the other, or there 
is a mutual interlacement of the pseudo-fragment and the 
syenite ; and imbedded masses also occur, which are not 
intermixed with the bounding rock at their junction. 
These phenomena are of the same description as those we 
observe with the constituent parts of granite ; for the con- 
cretions of felspar, quartz and mica, as is well known, are 
sometimes intermixed at their line of junction with each 
other, or there is no intermixture, or branches or veins 
from the different concretions mutually penetrate each 
other. Now, as it is universally admitted that the felspar, 
quartz and mica, in granite, have crystallised at the same 
time, it follows, that all mineral aggregates, such as the 
pseudo-fragments just mentioned, which exhibit similar 
phenomena, are to be viewed as instances of simultaneous 
or contemporaneous formation 
There rests upon the coarse granular syenite, exhibiting 
the characters already mentioned, strata of syenite, having 
the fine granular, compact, and slaty structures, ran- 
ging from NE, to SW., and dipping to the SE. under an 
* Even true fragments of various rocks, as of porphyry, syenite, &c, 
caused by agitations during the general crystallisation of the rock, may oc= 
c?ur in gi nnitc. 
