86 THE ORIGIN OF SPECIES 



discovered in these beds. Not long ago, paleontologists 

 maintained that the whole class of birds came suddenly 

 into existence during the eocene period; but now we 

 know, on the authority of Professor Owen, that a bird 

 certainly lived during the deposition of the upper green- 

 sand; and still more recently, that strange bird, the 

 Archeopteryx, with a long lizard-like tail, bearing a pair 

 of feathers on each joint, and with its wings furnished 

 with two free claws, has been discovered in the oolitic 

 slates of Solenhofen, Hardly any recent discovery shows 

 more forcibly than this how little we as yet know of 

 the former inhabitants of the world. 



I may give another instance, which, from having 

 passed under my own eyes, has much struck me. In a 

 memoir on Fossil Sessile, Cirripeds, I stated that, from 

 the large number of existing and extinct tertiary species; 

 from the extraordinary abundance of the individuals of 

 many species all over the world, from the Arctic regions 

 to the equator, inhabiting various zones of depths from 

 the upper tidal limits to 60 fathoms; from the perfect 

 manner in which specimens are preserved in the oldest 

 tertiary beds; from the ease with which even a fragment; 

 of a valve can be recognized; from all these circum- 

 stances, I inferred that, had sessile cirripeds existed 

 during the secondary periods, they would certainly have 

 been preserved and discovered; and as not one species! 

 had then been discovered in beds of this age, I concluded] 

 that this great group had been suddenly developed at thej 

 commencement of the tertiary series. This was a sor^ 

 trouble to me, adding as I then thought one moi 

 instance of the abrupt appearance of a great group of 

 species. But my work had hardly been published, when 



