64 POPULAE HISTORY OF THE AQUARIUM. 



whether they would be provided with exactly the same kind 

 of bed which they had been accustomed to^ and which was 

 most suitable to any movements they might desire to make*. 



On one subject there is no question. There is no doubt 

 that, when irritated, Sea-Pens throw out a strongly phos- 

 phorescent light. AVhen the animal is touched or pressed 

 it gives a luminosity, commencing at the point of contact 

 and proceeding up towards the pinnse. If the upper part 

 of the specimen be irritated, all parts below the contact 

 remain unaffected, while those above it emit phosphorescence. 



A beautiful result is obtained, although perhaps cruelly, 

 by throwing a Pennatula into fresh water, when it emits and 

 scatters brilliant sparks in every direction. 



YlRGULARIA MIllABILIS. 



Very nearly allied to Fennutula, but very much more 

 slender and elongated in form ; sometimes growing to the 

 length of five-and-twenty or thirty inches. It is of a straw - 

 colour, and growing all along on each side of the long stem 

 are polypiferous masses, each divided into six or seven lobes 

 or fingers, and at the end of each finger a most beautiful 

 eight-rayed star polype. The pinnse are not placed on each 

 side of the stem exactly opposite to each other, but each 



