158 OUR COMMON BRITISH FOSSILS. 



CHAPTER VI. 



FOSSIL WORMS (ANNELIDA). 



DARWIN recently showed how geologically important 

 is the common earth-worm. A biologist as intimately 

 acquainted with the life-histories of other insignificant 

 creatures would be able to prove that the most insig- 

 nificant of them plays some part or other in geological 

 operations. They may not be Founders of continents, 

 like the Foraminifera and the Corals ; but the world 

 would have been different in some way or another if 

 they had not existed. 



A Worm is the lowest member of a sub-kingdom 

 of animals on which perhaps more changes have been 

 rung than any other. It is an annulose, or ringed 

 animal. It forms the fundamental structure which 

 may be modified according to circumstances, into a 

 lobster, crab, scorpion, spider, butterfly, beetle, bee, 

 dragon-fly, cockroach, or house-fly ; besides other crea- 

 tures which crawl, fly, and swim. Throughout life it 

 may retain the primitive structure we are acquainted 

 with in the common earth-worm or lob-worm ; or 



