638 



ANNUAL REGISTER, 1810. 





mud colour, leaving the water un- 

 derneath perfectly clear. 



In order to ascertain if these 

 animals would materially alter their 

 size, or assume the figure of any 

 other known species of medusae, I 

 kept them alive for twenty-five 

 days, by careful!}' changing the 

 water in which they were placed ; 

 during which time, although they 

 appeared as vigorous as when first 

 taken, their form was not in the 

 slightest degree altered, and their 

 size but little increased. - By this 

 experiment I was confirmed in the 

 opinion of their being a distinct 

 species, as the young actineae and 

 medusae exhibit the form of the 

 parent in a much shorter period 

 than the above. 



In September 1806, I took at 

 Sandgate a number of the beroe 

 fulgens, but no other species : they 

 were of various dimensions, from 

 the full size down to that of the 

 medusa scintillans: they could, 

 however, be clearly distinguished 

 from the latter species, by their 

 figure. 



Since that time, I have fre- 

 quently met with the medusa scin- 

 tillans on different paths of the 

 coast of Sussex, at Tenby, and at 

 Milford haven. I have likewise 

 seen this species in the bays of 

 Dublin and Carlingford in Ire- 

 land. 



In the month of April, last year, 

 I caught a number of the beroe 

 fulgens in the sea at Hastings ; 

 they were of various sizes, from 

 about the half of an inch in 

 length to the bulk of the head of 

 a large pin. I found many of them 

 adhering together in the sea : 

 some of the larger sort were cover- 

 ed with small ones, which fell off 

 when the animals were handled ; 



and by a person unaccustomed to 

 observe these creatures, would 

 have been taken for a phosphoric 

 substance. On putting a number 

 of them into a glass containing 

 clear sea water, they still showed 

 a disposition to congregate upon 

 the surface. I observed that when 

 they adhered together, they show- 

 ed no contractile motion in any 

 part of their body, which explains 

 the cause of the pale or white co- 

 lour of the diffused light of the 

 ocean. The flashes of lightwhich 

 I saw come from the sea at Heme 

 Bay, were probably produced by 

 a sudden and general effort of the 

 medusae to separate from each 

 other, and descend in the water. 

 The medusa scintillans almost 

 constantly exists in the difterent 

 branches of Milford Haven that 

 are called pills. I have sometimes 

 found these animals collected in 

 such vast numbers in those situa- 

 tions, tiiat theyborea considerable 

 proportion to the volume of the 

 water in which they were con- 

 tained : thus, from a gallon of sea 

 water in a luminous state, I have 

 strained above a pint of these me- 

 dusae. I have found the sea under 

 such circumstances to yield me 

 more support in swimming, and 

 the water to taste more disagree- 

 ably than usual ; probably the dif- 

 ference of density, that has been 

 remarked at different times in the 

 water of the sea, may be referred 

 to this cause. 



All my own observations lead 

 me to conclude, that the medusae 

 scintillans is the most frequent 

 source of the light of the sea 

 around this country ; and by com- 

 paring the accounts of others with 

 each other, and with what I have 

 myself seen, I am persuaded that 



