356 THE BIOCOSMOS PARTICULARIZED. 



as his criterion and not the bones of the ver- 

 tebral column, making the division into blood- 

 less (invertebrate) animals and blooded 

 (vertebrates with their four classes fishes, 

 amphibians with reptiles, birds and mam- 

 mals). It may be added that there has been 

 a recent attempt to take the blood in its cor- 

 puscular constitution as the criterion for a 

 new classification of Animals, which, in its 

 wav is a return to the work of ancient Aris- 



*/ 



totle. 



But when it comes to putting into order the 

 four (or five) classes of Vertebrates the 

 fish, the reptile, the bird, and the mammal- 

 the modern anarchy of science breaks out 

 afresh with illuminating discord. The main 

 point is to arrange these so prominent and 

 well-known animal shapes into new divisions 

 which will not only show their differences 

 (which are plain enough), but their deeper 

 inter-relations. Among the many attempts 

 to re-classify the Vertebrates, we may here 

 set down that of Huxley as probably the best 

 known, beginning with Fishes: (1) Iclifhy- 

 opsida (fish-looking) in which the Fishes and 

 Amphibia are joined. (2) Sauropsida (liz- 

 ard-looking) in which the Reptiles and Birds 

 are brought together by anatomical homolo- 

 gues. This conjunction which seems now so 

 strange, is well-certified by evolution in the 



