Chapter V Echinoderms 



THE advent of the Echinodermata or 

 spiny-skinned animals marked an epoch- 

 making step in the course of animal pro- 

 gress. The Foraminifera were armoured 

 and capable of considerable movement, 

 but being incapable of expanding beyond 

 the single cell, remained mere ciphers 

 amongst the more progressive and rela- 

 tively bulky coelenterates. A few jelly- 

 fishes and anemones grew to a large size, 

 but being on the one hand the sport of 

 wind and current and on the other tied 

 to one spot, suffered in their capacity for 

 expansion. Coral may form vast masses, 

 but the individuals forming such masses 

 are all of negligible size. The Echino- 

 derms have, however, not only combined 

 defensive armour and weapons with great 



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