616 BIOLOGY. 



give the most clear and decisive answer. If we adopt 

 the last proposition, then the Birds must follow each 

 other thus : 



1. Fish-like Birds . . Palmipedes. 



2. lleptilian ,, . Grallte. 



3. Typical . . Gallinse. 



4. Thricozooid Birds . . Strutliionidae. 



According to this, the Aquatic Birds would occupy 

 the lowest rank, just as they have actually done hitherto 

 in all other systems. The three other families too do not 

 admit of any other position. But what is to be done 

 meanwhile with the large majority of other Birds ? They 

 would extend or pass beyond the Thricozoa, and have 

 thus no anatomical system whatever for their basis. 

 Besides, Humming-birds, Sparrows and Linnets would 

 in this way rank higher than the Gallinaceous and 

 Struthious Birds, which some indeed believe to be the 

 case, but without any proof, so that it is scarcely neces- 

 sary to abide by such an opinion. 



The Thricozoa must stand thus : 



1. Icthyoid . . Cetacea. 



2. Herpetoid . . Pachydermata. 



3. Omithoid . . Ruminantia. 



4. Typical . . All the remaining Thricozoa. 



In the systems now in vogue the Thricozoa certainly 

 follow in this manner, and no scruple whatever is made 

 of placing the Mice, Ant-eaters, Shrews, and Bats above 

 Elephants, Horses, and Deer. Yet apart from all this, 

 the former must pass beyond the Thricozoa, and would 

 thus likewise have no other organ as a foundation than 

 perhaps the organs of sense, of which there are but five, 

 while the families of Thricozoa not yet provided for are 

 much more numerous, namely, besides those named, the 

 Seals, Dogs, Bears, and Apes. 



The above methods of arrangement must be conse- 

 quently cast aside without limitation or reserve, although 

 they may have held good for hundreds of years. But 

 what does or will not hold good in an age that is devoid 

 of principles ? 



