INTRODUCTION. Iv 



Mineralogical and Chemical. 



(3) The four or more parts constituting " Eozoon " are iden- 

 tifiable with mineral developments more or less common in crys- 

 talline rocks that have undergone chemical changes, as ophites 

 and hemithrenes. Serpentine, which is an important component 

 of eozoonal parts, is notoriously a protean mineral, a product 

 of chemical alteration in other minerals (pseudomorphism), 

 and a prey to structural changes : chrysotile (a fibrous form) 

 and flocculite (a flocculent form) are examples of the latter. 



(4) ci Chamber-casts." Those constituting the acervuline va- 

 riety of "Eozoon" are identical with the rounded and variously 

 lobulated crystalloids of hornblende, augite, chondrodite, and 

 other minerals characteristic of hemithrenes of Scandinavia, Mas- 

 sachusetts, Saxony, Ceylon, Connemara, Tyree, and the Vosges. 

 Those of the lamellated variety are strictly paralleled by the 

 layers of similar minerals in the silo-carbacid gneisses of Norway, 

 Bavaria, North America, and elsewhere. All these examples are 

 demonstratively of mineral origin. 



(5) Eozoonists (Dawson, S terry Hunt, Giimbel), in taking the 

 rounded cylindrical and tuberculated t( grains " of pargasite &c. 

 in the coccolitic marbles of Scandinavia to be " chamber-casts " 

 and other organic structures, are obviously in error, the said 

 "grains" being crystalloids decreted by solvent action, as 

 proved by their often retaining not only the crystalline faces, 

 angles, and edges of the original mineral, but by the flocculent re- 

 siduum, on their surface, of the portions that have been removed. 



(6) "Proper wall" The typical form (separated aciculae with 

 calcareous interpolations) can be proved to be a modification 

 of true chrysotile ; moreover it occurs in cracks that have 

 been mechanically produced. 



(7) "Canal system," including "stolons." Clotules of floc- 

 culite (plainly resulting from serpentine that has undergone a 

 change) are frequently shaped into irregular configurations 

 (taken for this part) by some solvent or decreting process which 

 affected their component substance. Similar configurations 



