104 EVOLUTION THE RESULT OF CHEMICAL FORCES. 



animal creation. A genuine fish could never have developed 

 into it by any manner of gradual selective changes. What bene- 

 fit would it be to a fish to have simply a trace of an air-breathing 

 lung, or any fraction of one not capable of sustaining its life out 

 of water? What advantage would it be to a fish gradually to 

 get rid of the numberless little bones in its fins, down to the five 

 sets of phalangial bones, or gradually to develop jointed limbs 

 with double bones in the lower parts, together with collar and 

 shoulder bones ? These are only useful for walking on land, and 

 of course could be of no advantage to a fish until it had lungs 

 for breathing air. The two developments must advance pari 

 passu, and neither are of any utility until they are both in large 

 measure perfected. 



This amphibian order, the first development of land animals, 

 and represented by some gigantic forms during the Primary 

 epoch, seems to have been the prolific mother of races. But 

 nearly all the offspring, including the saurians, the lizards, the 

 flying reptiles, the dragons, the duck-billed monotremes, and the 

 marsupials, proved to be failures in the great plan of life, and 

 after a short but widely disseminated reign, either entirely or 

 very nearly passed out of existence. From the very important 

 fact that every family or order of the quadruped animals was 

 started out with the full equipment of structural bones, and 

 thereafter in its branchings immediately commenced to eliminate 

 or to modify these skeletal parts, I think it amounts almost to a 

 demonstration that each one sprung independently from the 

 same line or stem of full- structured, undiiferentiated, and primi- 

 tive animals. This line, in the nature of the case, could have 

 been no other than the great Carboniferous order of amphibians, 

 which we know to have been the prolific parent of all the earlier 

 orders of land vertebrates. Consequently the few living, and in 

 all cases degraded forms, like the lancelets (amphioxus), the mud 

 fishes (lepidosirens), and the duck-billed platipus (ornithorhyn- 

 chus), which have been so often brought forward by evolutionists 

 to represent intermediate classes or links, probably never had any 

 connection whatever with other orders, but are merely the 

 vanishing remnants of distinct and decaying families the last 



