CHAPTER V 
PAST HISTORY OF ANIMALS 
(PALZONTOLOGY) 
In the two preceding chapters we have noticed two of the 
great records of the history of animal life,—that preserved 
in observable structures, and the modified recapitulation 
discernible in individual development ; in this we turn to 
the third—the geological record. In the early days of the 
Evolution theory the modern science of Embryology was 
still in its infancy, and could furnish few arguments, and it 
was the opponents of the new theory rather than its sup- 
porters who appealed to Paleontology. They asserted that 
the palzontological facts refused to lend the support which 
the theory demanded. To their attacks the evolutionists 
usually replied by pointing out that the geological record 
was very incomplete. The numerous investigations which 
have since been carried on on all sides now show con- 
clusively that it was imperfection rather of knowledge than 
of the record which produced the negative results. We 
must, however, still acknowledge that, except in a few 
cases, there is but little certainty as to the precise pedi- 
gree of living animals, and seek for reasons to explain 
this. 
“Imperfection of the geological record.”—If we re- 
member the rule of modern Geology, that the past is to 
be interpreted by the aid of the present, there can be no 
difficulty in realising that the chances against the preserva- 
tion of any given animal are very great. Many are destroyed 
by other living creatures, or obliterated by chemical agencies. 
Except in rare instances, only hard parts, such as bones, 
