On Specimens of Eozoon Canadense. 209 
glauconite has penetrated the coarser portions only. This 
is very well seen in the beautiful specimens from Kempfen 
in Bavaria. All this applies to Eozoon. The most difficult 
part to findis its proper wall. The coarser canals are 
often present without the finer. The coarser parts of the 
canals are sometimes filled with serpentine, when the finer 
branches are filled with calcite or dolomite. The cells and 
laminz are sometimes quite manifest when the finer struc- 
tures are absent. All this is in perfect harmony with the 
analogy of other fossils. 
— SILy 
— ~~ 
Fig. 5. Slice of single lamina of Eozoon, magnified. (a) Tubulated wall; 
(b) Canal system ; both injected with Serpentine. 
Eozoon also agrees with other fossils in the independence 
of its form with reference to the mineral matter with which 
the cavities may be filled. This peculiarity commended it- 
self to the sagacity of Sir William Logan, and induced him 
to argue for the organic nature of Kozoon before its minute 
structures were known, and since these were investigated 
the argument has been much strengthened. The minerals 
serpentine, pyroxene and loganite are found filling the 
chambers, and the two former with dolomite and calcite oc- 
cupy the canals, which often present calcareous fillings in 
the finer ramifications, when the main stems are occupied 
with serpentine. These facts are readily explained if we 
assume cavities and tubes of definite form to be filled with 
minerals according to circumstances; but they are not ex- 
plicable on the supposition of a merely inorganic origin. 
They correspond perfectly with facts observed in the infiltra- 
tion and replacement of all classes of fossils, which often 
