M. Delesse on Globuliferous Rocks. . 
The globules in obsidian are usually more or less radiated, and 
sometimes have an exterior coat or layer. ‘They resemble much 
those found in the crucibles of a glass furnace when slowly cool- 
ed erlites and retinites, even when apparently compact, con- 
sist wholly of globules which may be distinguished when care- 
fully examined ; and the structure is very ine aay and spar- 
ingly concentric, with some cross fractures (fig. 
Normal globules with quartz.—Globules —— quartz pass 
quence of the solidification of a crystalline crust, The structure 
is either es or concentric, and both kinds may occur togeth- 
rays consist of feldspar needles or conoids separated by 
quartz ; oad both at the alga igo was centre there are often 
zones of feldspar alternating with 
The structure of the globules of the ‘pytomeride of Corsica is 
shown in the following magnified vi 
