360 JOURNAL OF THE PLYMOUTH INSTITUTION. 
Breccia and Cave-earth respectively, were very dissimilar. That 
of the older era did not include the Hyzena, which played so 
conspicuous a part in the Cavern history during the Cave-earth era, 
and whose agency, next to that of man, made Cavern-searching an 
important branch of science. 
That the deposits, with the constructive and destructive processes 
just described, were not only distinct and successive, but also very 
protracted, terms in the Cavern chronology is strikingly seen in 
considering the changes they indicate. 
Ist. During the period of the Breccia, there was a machinery 
capable of transporting from Lincombe or Warberry Hill, or both, 
or from some greater distance, fragments of dark-red grit, varying 
in size from pieces four inches in mean diameter to mere sand, and 
lodging them in the Cavern. This so completely passed away that 
nothing whatever was carried in, but the deposit already there was 
covered with a thick sheet of Stalagmite obtained through the 
solution, by acidulated water, of portions of the limestone in the 
heart of which the Cavern lay. This stage having also ended, the 
Stalagmite was broken up by some natural agency, the exact 
character of which it is difficult to ascertain, but which achieved 
its work, not by one effort, but by many in succession, and much of 
at least the Breccia it covered was dislodged and carried out of the 
Cavern. This re-excavating period having in like manner come to 
a close, a second deposit was introduced; but, instead of consisting 
of dark-red sand and stones as in the former instance, it was made 
up of a light-red clay, and in it were embedded small fragments 
of limestone, which, from their angularity, could not have been 
rolled, but were in all probability supplied by the waste of the 
walls and roof of the Cavern itself. 
2nd. The paleontology of the two deposits is perhaps even more 
significant of physical changes and the consequent absorption of 
time. When the Cavern-haunting habits of the Hyena are remem- 
bered, it will be seen that his entire absence from the fauna of the 
Breccia, and his remarkable preponderance in that of the Cave- 
earth, renders it eminently probable that he was not an occupant 
of Britain during the earlier period. To accept this, however— 
and there seems to be no escape from it—is to accept the opinion 
that between the eras of the Breccia and of the Cave-earth it had 
become possible for the Hyena to reach this country, since he was 
