ANTHOZOA IIYDROIDA. 27 



brightest diamonds."* These interesting- observations were 

 soon afterwards confirmed by others of a similar nature made 

 by the Rev. D. Landsborough. He found the Sertularia 

 polyzonias and Plumularia cristata to give out little light, 

 perhaps from some unfavourable condition of the specimens ; 

 but the Laomedea geniculata " was very luminous, every cell 

 for a few moments becoming a star ; and as each polype had 

 a will of its own, they lighted and extinguished their little 

 lamps, not simultaneously, but with rapid irregularity, so that 

 this running fire had a very lively appearance." In another 

 experiment with the same species, and when in all probability 

 the polypes were dead, bright sparks were elicited on roughly 

 handling the polypidoms, which also " emitted a strong smell 

 of phosphorus."" -f* After being dried or wasted by exposure 

 to the air or rain, or by putrefaction, these zoophytes give no 

 further evidence of the existence of an excretion which ap- 

 pears given to them as a means of fraying away their enemies, 

 for it is never made visible to us, unless under circumstances 

 that imply a feeling of injury and alarm. 



* Ann, and Mag. Nat. Hist. vii. p. 281. I add another passage from a subsequent 

 paper of Mr. Hassall's in vol. viii. p. 342, of the same journal : " Numerous friends, 

 among others G. J. Allman, Esq., of Bandon, can bear witness to the exceeding 

 brilliancy of the phosphorescent light emitted by a great variety of species which I was 

 frequently in the habit of exhibiting to them. Once each week I received from the 

 master of a trawling-vessel on the Dublin coast a large hamper of zoophytes in a 

 recent state ; in the evening these were taken into a darkened room, and the spec- 

 tators assembled ; I then used to gather up with my hands as much of the contents 

 of the hamper as I could manage, and, tossing them about in all directions, thousands 

 of little stars shone out brightly from the obscurity, exhibiting a spectacle, the 

 beauty of which to be appreciated must be seen, and one which it has been the lot of 

 but few persons as yet to have looked upon. Entangled among the corallines were 

 also numerous minute luminous Annelides, which added their tiny fires to the gene- 

 ral exhibition." 



+ Ann. and Mag. Nat. Hist. viii. p. 258-9. The priority in discovery of phos- 

 phorescence in Hydroid Zoophytes has given rise to some discussion between Prof. 

 Forbes and Mr. Hassall. See Ann. Nat. Hist. xii. p. 118-120 ; and p. 42, comp. 

 with p. 



