CHAPTER V. 



PAST HISTORY OF ANIMALS. 



PALEONTOLOGY. 



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. From Morphology many 

 conclusions as to the course of evolution have been drawn ; 

 the study of form must indeed, by itself, in time have led to 

 the doctrine of evolution, that the present is the child of 

 the past. 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 supporters who appealed to 

 Palaeontology. They asserted that the palaeontological facts 

 refused to lend the support which the theory demanded. 

 To their attacks the evolutionists then chiefly sought to 

 reply by pointing out that the geological record was very 

 incomplete. The numerous investigations which have since 

 been carried on on all sides, now show conclusively 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 relatively few cases, little 

 is known of the ancestors of living animals, and seek for 

 reasons to explain this. 



Reasons for the "Imperfection of the Geological Record" 



If we remember 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 pre- 



