6io THE POPULAR SCIENCE MONTHLY. 



ness. Most interesting of all for our present purpose, however, are the 

 bones of contemporary reptiles and birds which this Nature-printing 

 rock incloses for the behoof of modern naturalists. One such reptile, 

 known as compsognathus, may be regarded as filling among its own 

 class the place filled among existing mammals by the kangaroo. It 

 was a rather swan-like, erect saurian, standing gracefully on its hind- 

 paws, with its fore-legs free, and probably dragging its round tail be- 

 hind it on the ground as a support to steady its gait. The neck was 

 long and arched, and the head small and bird-like in shape ; but the 

 jaws are armed with sharp and powerful teeth, as in the pterodactyls. 

 Altogether, compsognathus must have looked in outward appearance 

 not at all unlike such birds as the auks and penguins, though its real 

 structural affinities lie rather with the emus and cassowaries. The 

 apteryx or kiwi of New Zealand, which is a bird that does not fly, be- 

 cause it has no wings worth mentioning to fly with, approaches even 

 nearer in the combination of both points to this very bird-like oolitic 

 reptile. 



Even compsognathus himself, however, though very closely allied 

 to the true birds, can not be held to stand as an actual point in the 

 progressive pedigree, because in the very same Solenhofen slates we 

 find a real feathered bird in person. Accordingly, as the two were 

 thus contemporaries, the one could not possibly be the direct ancestor 

 of the other. Nevertheless, it is certainly from some form very closely 

 resembling compsognathus that the true birds are descended. We 

 have only to suppose such a reptile to acquire forestine habits, and to 

 begin jumping freely from tree to tree, in order to set up the series 

 of changes by which a true bird might be produced. But the first 

 historical bird of which we know anything, the archseopteryx of the 

 Solenhofen slate, still remains in many points essentially a reptile. It 

 is only bird-like in two main particulars ; its possession of rudiment- 

 ary wings and its possession of feathers. From the popular point of 

 view, these two particulars are decisive in favor of its being consid- 

 ered a bird ; but its anatomical structure is sufficient to make it at 

 least half a reptile ; and eminent authorities have differed (with their 

 usual acrimony) as to whether it ought properly to be called a bird- 

 like saurian or a lizard-like bird. There is nothing like a mere ques- 

 tion of words such as this to set scientific men or theologians roundly 

 by the ears for half a century together. 



Archaeopteryx, then, is just compsognathus provided with rude 

 wings and feathers, but in most other respects a good lizard. Unlike 

 all modern birds, it has a long tail composed of twenty separate verte- 

 brae ; and opposite each vertebra stand two stout quill-feathers, so 

 that instead of forming a fan, as in our own pigeons and turkeys, they 

 form a long pinnate series like the leaflets of yonder palm-branch. 

 These feathers, like all others, show traces of their origin from the 

 scales of lizards. Moreover, in the jaw are planted some small conical 



