320 Jee de aVOGE 
conclusion that A in its entirety had crystallized before the com- 
mencement of the crystallization of B. As to the conceptions 
allotriomorphism, hypidiomorphism, and panidiomorphism, we 
refer to the petrographic textbooks. 
_ Inclusions of an idiomorphic, primary crystal A in B implies 
that A had crystallized earlier than the surrounding parts of B. 
But if A only appears in the exterior zone of B, the interior part 
of B may have crystallized earlier than A. And even if inclusions 
of idiomorphic crystals of A appear evenly distributed over the 
whole of B, also in the kernel of B, it may be that part of A also 
may have crystallized at a later stage. Asan example, idiomorphic 
crystals of apatite, as is known, in many cases appear in the oldest 
silicates and in the ore minerals, indicating that the apatite crystal- 
lized before the commencement of the solidification of the iron 
ore and the silicates. But I warn against the conclusion, which is 
often drawn, that the apatite in its entirety crystallized during 
the earlier stage. 
Further, it must be taken into consideration that small portions 
of the mother-liquid occasionally may be inclosed or included 
in a mineral during its growth. As example we refer to the 
well-known zonally arranged glass-inclusions in leucite, sanidine, 
etc., in many dyke and effusive rocks. If corresponding magma- 
inclusions occur in deep-seated rocks, a complete crystallization of 
this material will take place. Thus the result will be inclusions 
in the host of a later-crystallized mineral. 
Inclusions of mineral A in mineral B may furthermore be due 
to the fact that A originally, at high temperature, occurred as a 
solid solution in B, and that afterward, owing to reduced solubility 
by decreasing temperature, A separated from the solid solution. 
As an example we refer to the well-known inclusions of perthitic 
albite or albite-oligoclase in the microcline of granites, etc. The 
microcline (or orthoclase) dissolved about 28 per cent Ab+An, 
the greater part of which later separated during refrigeration. 
Further may be mentioned the secretion of lamellae of monoclinic 
pyroxene in orthorhombic pyroxene’ and conversely also of ortho- 
«Cf. the general account in my publication in Tscherm. min. u. petrogr. Mitt., 
Vol. XXIV (1905), pp. 537-42. 
