vi 



are honestly stated, and the opposite opinion weighed 

 without prejudice in the balance of induction. As 

 regards myself, the more I extend my observations 

 the more fixed and settled is my conviction. Should 

 the agitation of this very curious subject excite others 

 to the enquiry (and it seems to have already roused 

 M. Virey in France), it will accomplish something; 

 and should future investigation prove me in error, I 

 shall cheerfully acknowledge my mistake ; my con- 

 clusions may ultimately be found incorrect, but the 

 registered facts will still remain the same. Unfettered 

 by any hypothesis or preconceived opinion, I shall 

 continue my researches and pursue my experiments. 

 In order to afford a better illustration of some of the 

 luminous animals, terrene as well as marine, described, 

 and a phenomenon connected with the flight of the 

 spider, a plate has now been added to the volume, 

 from the lithographic press of Mr. Hullmandel. 



What has been withdrawn is substituted by new 

 and interesting matter obtained from various sources, 

 intermixed with details of original research and remark: 

 in the disposal of these accumulated materials I have 

 endeavoured to be select, and as little diffuse as pos- 

 sible. In reference to the phosphorescence of the 

 ocean, I confess myself under considerable obligations 

 to Mr. Thompson's curious and original " Zoological 

 Researches," a work that bears in addition to its other 

 interesting qualifications the evidence of much industry. 

 To its ingenious author we owe the discovery of that 

 " rara avis" the pentacrinus europceus, found in a living 

 form in the Cove of Cork. 



