TERMINOLOGY. . 186. 



If the individuals connected with each other become very 

 small, but join in a great number into a groupe of crystals, 

 globular forms result, which are sometimes perfect, some- 

 times very imperfect. Their surface is drusy, or covered 

 with asperities, where it has not been disfigured in its 

 formation, or by subsequent accidental circumstances. In 

 their interior we may still discover the direction of the 

 constituent individuals, which, in most cases, corresponds 

 to the direction of the radii of a sphere ; they begin in the 

 centre, and terminate at the surface. Imbedded globular 

 shapes, like imbedded crystals, are complete on all sides, 

 and leave an impression of their form in the mass from 

 which they have been detached. 



Several globular masses of this kind, if attached to one 

 another, may produce reniform and botryoidal shapes, 

 which, however, require to be distinguished from those de- 

 scribed in . 183. 



The loose or imbedded globular shapes differ from grains 

 and angular masses (. 160.), in as much as they are not 

 simple minerals. Examples of imbedded globular shapes oc- 

 cur in prismatic Iron-pyrites, in prismatic Azure-malachite, 

 and other species ; the same Malachite presents also reni- 

 form and botryoidal shapes formed from imbedded crystals. 



. 183. IMITATIVE SHAPES ARISING OUT OF THE 

 GEODES OF CRYSTALS. 



There are three different kinds of imitative 

 shapes resulting from geodes of crystals : 1. Those 

 in which the individuals spring from, or are attached 

 to a common point of support ; 2. Those in which 

 the individuals form one the support of the other ; 

 and 3. Those in which the support is cylindrical, 

 sometimes a simple line, sometimes a tube. 



Among those of the first division we find the implanted 

 globular shapes. They arise, if very thin, capillary crystals, or 



