108 



RAPID CHANGE OF FOmU 



shape of these wonderful filaments are very 

 various, some being of a very great length, and 

 so fine that a microscope of high power can 

 hardly distinguish them ; while others are only 

 two or three times the length of the capsule that 

 contained them^ and covered with an armature of 

 short hairs even more minute than themselves. 



It is easy enough to see these singular organs, 

 even with the aid of a good hand-lens ; but with 

 a microscope nothing more is required than to 

 cut off part of a tentacle, get it well in the field 

 of the microscope, and then apply pressure: 

 some of the capsules will dart forth their threads 

 almost immediately, but others will require 

 greater force before they will evert themselves. 



The crass may often be passed by without 

 observation if it does not choose to display itself ; 

 for when closed nothing appears but a round 

 mass of sand and broken shells, about the size of 

 a penny-piece, and projecting so slightly above 

 the sand that an inexperienced eye would see 

 nothing remarkable in it. This unpromising 

 aspect is assumed when the creature has had a 

 large dinner, or when it is alarmed. It is rather 

 curious to see how suddenly a magnificent speci- 

 men of living flower collapses into a shapeless, 

 •nd not at all pleasing knot of sand, stone, and 



