CHAPTER V 

 BIOLOGICAL PALAEONTOLOGY 



IN the small space available it is impossible to discuss, 

 or even to catalogue, the various biological problems 

 towards whose solution Palaeontology can contribute. 

 Since detailed reference to the many branches of such 

 research is impracticable, an attempt has been made to 

 give a general account of the broad outlines of phylo- 

 genetic evolution. Long and tedious study will be 

 necessary before many of the propositions here made 

 can be proved or disproved ; any stimulus to such effort, 

 with either intent, that may perchance proceed from 

 this chapter, would amply justify inclusion of theoretical 

 matter in an introductory essay. The whole chapter is 

 intended to convey hints as to lines of investigation 

 that cannot fail to prove profitable ; it is in no sense 

 an epitome of all that has been achieved towards eluci- 

 dation of evolutional problems. 



(I) PHYLOGENY AND MORPHOGENY 



The stratigraphical record, whose interpretation is 

 ultimately based upon the incontrovertible evidence of 

 superposition, repays in full the debt it owes to palaeon- 

 tological principles, since it supplies a historical sequence 

 for the faunas of successive periods. It is possible to 

 trace the direction and progress of evolution in its opera- 

 tion through vast ages of time with confident knowledge 

 that the order of events is established. In spite of the 



