54 LECTURES 



its branching life-descent are now seen in the living 

 faunae existing upon the surface of the world of our day, 

 or teeming in our oceans and inland waters. Palaeontol- 

 ogy, the science of the organic forms of the past, imper- 

 ceptibly merges into zoology, the science of the organic 

 forms now in existence. And, this growth has never been 

 checked for an instant; the same laws are now in opera- 

 tion as have been in operation throughout all geologic 

 times and ages; many animals now in existence are 

 doomed to utter extinction, some in the near future, 

 others in ages to come. A host of others will send down 

 into futurity their descendants, and from them will un- 

 doubtedly arise, in time, new forms to furnish the world 

 with still different species, in many cases totally unlike 

 their nowaday ancestors, as those ancestors, the species 

 now with us, are totally unlike the forms from which 

 they in turn were derived. Even the topographical phys- 

 ical aspects of the world itself must change, as many, 

 many of those changes are now gradually going on and 

 are well known to science; their contemplation, and care- 

 ful study, and comparison with the happenings of past 

 ages, which in so many instances are so clearly written 

 upon Nature's historic pages, form one of the very grand- 

 est fields of research open to the intellectual activity of 

 the mini of man. 



