222 PUZZLES IN PALEONTOLOGY. 



Coal period, and, though the remains of insects are abundant, 

 there were as yet none of the nectar-sucking, pollen-loving species. 

 Neither Lepidoptera nor Hymcnoptera are found. 



In the next age— the Permian — the remains of reptiles are, for 

 the first time, found. I^ut we can hardly suppose that they now 

 made their first appearance in the world. They are highly 

 specialised in many ways ; their teeth are distinctly differentiated 

 into incisors and canines, and they show strong affinities to the 

 lowest mammals in the structure of their pectoral and pelvic 

 girdles. In one important ])articular they show an embryonic 

 condition like that of the Ganoids— their vertebral column is only 

 partially ossified. 



The Mesozoic period — from the Permian to the end of the 

 Cretaceous — is the great age of reptiles. They attain dimensions 

 unequalled by any other animal. Even the whale could not 

 compete in size with Atlantosaurus, which measured forty feet in 

 height and from eighty to a hundred feet in length, and whose 

 thigh-bone exceeds in length the whole body of a power- 

 ful man. It belonged to the wonderful order of Deinosaurs, for 

 whose fate I always feel a sympathy. In their organisation they 

 approached as nearly as any reptile has ever done to warm- 

 blooded creatures. Some were of stupendous size ; others rivalled 

 true birds in their fliglit ; others were furnished with rows of ter- 

 rible, trenchant teeth, showing their carnivorous nature. Yet all 

 these deinosaurs perished in the age that brought them forth. 

 They would have left no testimony of their existence but their 

 bones, had we not reason to sup]:)ose that some of the deinosaurs 

 did become warm-blooded, and died out as deinosaurs, to spring 

 into existence as birds. The small deinosaur found with the first 

 l)ird in the lithographic slate of Solenhaufen is, like the first bird, 

 of so mixed a character in its whole anatomy, that it is hard to 

 say where the rejitile ends and where the bird begins. Perhaps 

 we may venture to conjecture that the first bird of Solenhaufen, 

 with its toothed beak and long reptilian tail furnished with 

 feathers, and with its rei)tilian hand ending a bird-like wing, repre- 

 sented a form in which the arterial had for the first time been 

 (■()in])letelv cut off from the venous blood ; and that the bird-like 

 reptile, Co/iipsognatlios, had still impure blood in its veins. 



