56 THE WHENCE AND THE WHITHER OF MAN 



tive systems. The higher groups of this kingdom had 

 developed all, or nearly all, the tissues used in build- 

 ing the bodies of higher animals — muscular, reproduc- 

 tive, connectile, glandular, nervous, etc. But these are 

 mostly very diffuse. The muscular fibrils of a jelly- 

 fish are mostly isolated or parallel in bands, rarely in 

 compact well-defined bundles. The tissues have gener- 

 ally not yet been moulded into compact masses of defi- 

 nite form. There are as yet very few structures to 

 which we can give the name of organs. To form organs 

 and group them in a body of compact definite form 

 was the work pre-eminently of worms. The material 

 for the building was ready, but the architecture of the 

 bilateral animal was not even sketched. And different 

 worms were their own architects, untrammelled by con- 

 vention or heredity, hence they built very different, 

 sometimes almost fantastic, structures. 



We must remember, too, the great age of this group. 

 They are present in highly modified forms in the very 

 oldest palaeozoic strata, and probably therefore came 

 into existence as the first traces of continental areas 

 were beginning to rise above the primeval ocean. 

 They are literally " older than the hiUs." They were 

 exposed to a host of rapidly changing conditions, very 

 different in different areas. This prepares us for the 

 fact that the worms represent a stage in animal life 

 corresponding fairly well to the Tower of Babel in bib- 

 lical history. The animal kingdom seems almost to 

 explode into a host of fragments. Our genealogical 

 tree fairly bristles with branches, but the branches do 

 not seem to form any regxilar whorls or spirals. Few 

 of them have developed into more than feeble growths. 

 They now contain generally but few species. Many of 



