3 88 HISTORICAL PALEONTOLOGY. 



period similarly surprises us without any prophetic annuncia- 

 tion from the older Jurassic. 



Many other instances could be given; but enough has been 

 said to show that there is a good deal to be said on both sides, 

 and that the problem is one environed with profound difficul- 

 ties. One point only seems now to be universally conceded, 

 and that is, that the record of life in past time is not interrupted 

 by gaps other than those due to the necessary imperfections of 

 the fossiliferous series, to the fact that many animals are in- 

 capable of preservation in a fossil condition, or to other causes 

 of a like nature. All those who are entitled to speak on this 

 head are agreed that the introduction of new and the destruc- 

 tion of old species have been slow and gradual processes, in no 

 sense of the term " catastrophistic." Most are also willing to 

 admit that "Evolution" has taken place in the past, to a 

 greater or less extent, and that a greater or less number of so- 

 called species of fossil animals are really the modified descend- 

 ants of pre-existent forms. How this process of evolution has 

 been effected, to what extent it has taken place, under what 

 conditions and laws it has been carried out, and how far it 

 may be regarded as merely auxiliary and supplemental to some 

 deeper law of change and progress, are questions to which, in 

 spite of the brilliant generalizations of Darwin, no satisfactory 

 answer can as yet be given. In the successful solution of this 

 problem if soluble with the materials available to our hands 

 will lie the greatest triumph that Palaeontology can hope to 

 attain; and there is reason to think that, thanks to the guiding- 

 clue afforded by the genius of the author of the 'Origin of 

 Species/ we are at least on the road to a sure, though it may 

 be a far-distant, victory. 



