KrainliKitloii of So-called Cannel Coal. — Penhallou). 335 
the original organic matter with the elimination of the elements 
of water. When such changes occur, the modified parts ac([uire 
a darker color which eventually become l)lack. assume a granular 
form and dispose themselves in accordance with the particular 
nature of the molecular changes in the material as a whole. This 
has elsewhere* Ijeen shown to produce viuy peculiar etfects, as in 
modification of the structure of Nnndtophi/ton. In this it is 
possiV)le to find a satisfactory explanation of the (listril)uti()n of 
granules about the surfaces of air tulu^s or internal fissures in 
such a way as to produce the appearance of a cell wall. 
The presence of tulnilar ramuli is a condition which, without 
critical examination, might seem to justif_y the opinion that my- 
celia had penetrated the bod}- and become per maneuth' preserved. 
This necessitates the supposition that (a) the material of the rods 
was once soft and that when in that condition it had AowcmI over 
and engulfed the associated fungi, or {h) that while plastic, it 
possessed nutriti\e i)roi)erties and was readily penetrated liy 
fungi. The total al)sence of lines of fiow otters serious opposi- 
tion to the first hypothesis, and indicates that the rods were, 
from the first, of the form and general charactin- now found. 
The second hypothesis is probably not admissible for ri'asons 
which will appear later, although it is undoubtedly true that the 
rods were originally composed of. a soft and even viscous sub- 
stance. 
It is furthermore found that the ramuli are not septate, liut 
form continuous simple or l)ranching tul)es; their l>ranching 
is irregular and not determined with that uniformity which is 
consistent with the growth of organic structure; the tubes are 
irregular and often contain side pockets such as no vegetable 
structure is known to liave, but such as might readily be formed 
under certain conditions of contraction in tiic surrounding mass. 
Also, the remarkable disposition of these tubes is wholly incon- 
sistent with their character as possil)le vegetable structures. 
Precisely siinil;ir tidies mny l)e formed under certain conditions. 
in any plastic material. It is a matter of conimon experience in 
the preparation of glycerine jelly mounts. that if a somewhat ex- 
cessive pressure l)e :ipi)lied to the ccntrMl iircM of the cover glass, 
the latter will be slightly Itent down below tiu^ line of the margin. 
Upon removal of the pressure after the jelly has hardened, the 
*Trans. Royal Soc.Can.vrn. iv. 24-25 Amkijic.w Gkologist. i.v. p. 360. 
