PALEONTOLOGY 111 



ticulates seem to have been as highly-organized and 

 as well-defined then as at present. 



The sub-kingdom of Radiata shows also a great 

 lack of progress. The Crinoids and Star-fishes of 

 the Silurian were as highly-organized as are the living 

 species of these classes, while the Sea-urchins of 

 to-day are not superior to the oldest known fossil 

 forms. 



The coral-forming Polyps which have persisted 

 through nearly all geological time still exist in large 

 numbers, but with little change and no progress 

 towards a more complex structure. 



That which is most noticeable in all the classes of 

 all the sub-kingdoms of invertebrates through the 

 long ages is the small amount of change in structure 

 and the lack of progress. Professor Huxley in de- 

 livering the anniversary address to the Geological 

 Society for 1870, quotes the following from an address 

 before the same society in 1862: 



" If we confine ourselves to positively ascertained 

 facts, the total amount of change in the forms of ani- 

 mal and vegetable life since the existence of such forms 

 is recorded is small. When compared with the lapse of 

 time since the first appearance of these forms, the 

 amount of change is wonderfully small. Moreover, 

 in each great group of the animal and vegetable 

 kingdoms, there are certain forms which I termed 

 Persistent Types, which have remained, with but very 

 little apparent change, from their first appearance to 

 the present time. 



"In answer to the question, 'What then does an 

 impartial survey of the positively ascertained truths 

 of paleontology testify in relation to the common 

 doctrines of progressive modification, which suppose 

 that modification to have taken place by necessary 

 progress from more to less embryonic forms, from 



