190 WALKS AND TALKS. 



and from an eighth to half an inch in diameter. This is simply 

 a pile of little button-like discs, each one with a hole through 

 the center, and some radial striae on the flat sides. So there 

 is a perforation through the whole length of the stem. Some- 

 times several of the segments remain attached together; but 

 generally, they are separated and scattered through the rock. 

 In some European countries they have long been known as 

 " St. Cuthbert's beads." We find them in great abundance 

 in the drift of the Northwestern States. At the top of the 

 stem we find a little urn composed of many stony plates 

 nicely joined together by their edges. The urn has a cover 

 similarly formed. Most of these bodies are found disjointed 

 ill the rocks ; but .there is one which seems to have held 

 together very firmly (Car-y-oc'^ri-nus) and is found in the 

 Niagara strata almost everywhere. The external surfaces of 

 the plates of the cup are elaborately chased and embossed ; 

 but this I must tell you is not an armed and rooted crinoid ; 

 it is a Cystid, having no arms and with, a tail-like stem. In 

 the true crinoids we find a row of arms generally ten rising 

 from the border of the urn or cup; and these often branch 

 or give off a delicate fringe. The arm and its subdivisions 

 are composed of flattened stony plates or pieces joined 

 together according to the general plan of the animal. 



We thus see that when nature adopts a particular method 

 for the construction of one part of an animal, she pursues 

 faithfully the same method in the formation of all the parts. 

 Thus it appears that the works of nature are formed according 

 to plans. Any thing which is a plan has been thought out. 

 The plans of Nature are the expressions of mind. 



XXXIII. THE KINO CRAB'S GRANDFATHER 

 AND OTHER GRANDFATHERS. 



CAMBRIAN FOSSILS. 



ONE who strolls along the coast of New England or the 

 contiguous islands will notice many things "cast up by the 

 sea," but one of the most interesting is the King Crab, 



