86 



Where is the advance? And even among 

 mammals, those of the Triassic and Oolitic spe 

 cies differ from those of the present no more 

 than these last differ from one another. Where 

 here do we find advance ? 



Professor Huxley took each great division 

 of the animal world which was remarkable for 

 a long range of period throughout the geologi 

 cal series and tried to ascertain what had been 

 the advance from simple to complex structure. 

 Let us glance briefly at a few of his conclu 

 sions. The Protozoa range throughout the 

 whole geological series from the lower Silurian 

 to the present day ; the most ancient forms are 

 exceedingly like those that now exist ; they 

 are not more embryonic or less differentiated. 

 Among the Coelenterata the Tabulate Corals 

 range from the Silurian to the present day ; the 

 ancient Heliolites are quite as highly organized 

 as our present Heliopora. Among Molluscs, 

 he asks " In what respect is the living Wald- 

 heimia less embryonic, or more specialized, 

 than the paleozoic Spirifer ....?" And 

 conversely he asks in what sense Loligo or 

 Spirula are in advance of the Belemnite. It is 



