114 Professor Oweri) [April 12, 



this planet, there has, however, plainly been an ascent and progress in 

 the main. 



Although the mammalia, in regard to the plenary development of 

 the characteristic orders, belong to the Tertiary division of geological 

 time, just as " Echini are most common in the superior strata ; 

 Ammonites in those beneath, and Producti with numerous Encrini 

 in the lowest "* of the secondary strata, yet the beginnings of the class 

 manifest themselves in the formations of the earlier preceding division 

 of geological time. 



No one, save a prepossessed Uniformitarian, would infer from the 

 Lucina of the permian, and the Opis of the trias, that the La- 

 mellibranchiate Mollusks existed in the same rich variety of develop- 

 ment at these periods as during the tertiary and present times ; and no 

 prepossession can close the eyes to the fact that the Lamellibranchiate 

 have superseded the Palliobranchiate bivalves. 



On negative evidence Orthisina, Theca, Producta, or Spirifer are 

 believed not to exist in the present seas : neither are the existing genera 

 of siphonated bivalves and univalves deemed to have abounded in 

 permian, triassic or oolitic times. To suspect that they may have then 

 existed, but have hitherto escaped observation, because certain 

 Lamellibranchs with an open mantle, and some holostoraatous and 

 asiphonate Gastropods, have left their remains in secondary strata, is 

 not more reasonable, as it seems to me, than to conclnde that the pro- 

 portion of mammalian life may have been as great in secondary as in 

 tertiary strata, because a few small forms of the lowest orders have 

 made their appearance in triassic and oolitic beds. 



Turning from a retrospect into past time to the prospect 

 of time to come, — and I have received more than one inquiry 

 into the amount of prophetic insight imparted by Palaeontology — 

 I may crave indulgence for a few words, of more sound, perhaps, 

 than significance. But the reflective mind cannot evade or resist the 

 tendency to speculate on the future course and ultimate fate of vital 

 phenomena in this planet. There seems to have been a time when life 

 was not ; there may, therefore, be a period when it will cease to be. 



Our most soaring speculations still show a kinship to our nature : 

 we see the element of finality in so much that we have cognizance of, 

 that it must needs mingle with our thoughts, and bias our conclusions 

 on many things. 



The end of the world has been presented to man's mind under 

 divers aspects : — as a general conflagration ; as the same, preceded by 

 a millennial exaltation of the world to a Paradisiacal state, — the abode 

 of a higher and blessed race of intelligences. 



If the guide-post of Palaeontology may seem to point to a course 

 ascending to the condition of the latter speculation, it points but a very 

 short way, and in leaving it we find ourselves in a wilderness of con- 



* A generalisation of WILLIAM SMITH'S, justly regarded by EDWARD 

 FORBES and other philosophical Naturalists as of higher importance than the 

 identification of strata by species. 



