BIRD OR REPTILE WHICH f 721 



make their acquaintance in a mummified or skeletonized form in mu- 

 seums. It cannot but strike the visitor to any zoological collection 

 where the vertebrated section is well represented that the cases de- 

 voted to the reptilian group contain forms so divergent as the tortoise 

 and the lizard, the snake and the alligator. If, however, the eye be 

 permitted to pass to the sections on either hand on the one side, to 

 the amphibious animals, such as the frogs and newts, and on the other, 

 to the birds it is impossible not to perceive that the contrast is very 

 great. A careless or inexperienced classifier might, perchance, be 

 tempted to relegate the lizard to a place among the amphibia, near to 

 the newts, or vice versa; but the most unobservant of men could never 

 locate a snake among the birds, nor set a turtle or a crocodile on the 

 same shelf with the swallow or the golden-crested wren. 



The first and lowest link of the reptilian segment in the great chain 

 of animal existences commences just above the highest of the am- 

 phibian assemblage, and is constituted by the river and mud loving 

 tortoises and the turtles of the warmer seas ; while the highest now 

 living embraced the Crocodilian family, in whose membership are in- 

 cluded the alligators and jacars of the New World, the crocodiles of 

 the Ganges and the gavials of Northern Africa. The gap between 

 these extremes is filled up by various intermediate gradations. To the 

 tortoises succeeds, according to our best classifiers, a powerful race of 

 long-necked ancient mariners the plesiosaurs which hunted their prey 

 by the sea-coasts of the geological middle ages, where they left their 

 bones, the sole testimony to the existence of their race, which became 

 extinct before the chalk-cliffs of England were completed, however long 

 ago that may be. After them comes the large group of the true lizards, 

 comprising, along with several extinct orders, the chameleons, the liz- 

 ards, and the geckos, both the latter being familiar enough to Conti- 

 nental travelers on sunny spots in Southern Europe ; the geckos, espe- 

 cially, attracting attention by their habit of running on ceilings and 

 perpendicular walls, by their sucker-formed toes. The next cohort em- 

 braces the serpents the pythons and boas, endued with a power of 

 crushing almost unsurpassed in the animal kingdom ; and the rattle- 

 snakes and cobras, carrying swift and certain death in the lightning 

 stroke of their head. The next place is assigned to the great fish- 

 lizards, or ichthyosaurs, which frequented the deeper waters of the 

 same seas as the plesiosaurs, of whose existence also all knowledge 

 would have perished forever, since they died out leaving no representa- 

 tive to continue their line, had not the kindly mud of the bottom pre- 

 served for us fragments of their history in their disjointed bones. 

 Advancing from these "dragons of the prime" we again reach the 

 crocodiles, the most specialized of modern reptiles. 



Although between the highest and the lowest of these forms there 

 is nothing like the close bond of union which connects the most dis- 

 tantly related of the birds, yet these diverse families have many charac- 

 \oh. xiii. 46 



