350 OSSEnvAtlONS OK LUMINOUS ANIMAES,*- 



The Imniiious The luminous animalcule, discovered by Foj*ster off the, 

 Fo'rster!" '^ ° Cape of Good Hope, in his voyage round the world, bears 

 so stronga resemblance to the medusa scintillans, that I aia 

 much disposed to bclicre them the same. He describes his 

 animalcule as bein^ a little gelatinous globule, less than the . 

 head of a piu ; transparent, but a little brownish in its co- 

 lour; and of so soft a texture, that it was destroyed by the 

 slightest touch. On being highly magnified, he perceived on 

 one side a depression, in which there was a tube that pass- 

 cd into the body, and communicated with four or five intes- 

 tinal sacs. The pencil drawings he made on the spot are in 

 the possession of Sir Joseph Banks, by whose permission 

 engravings from them are subjoined to this paper. By com- 

 paring these with the representations of the medusa scin- 

 tillans, and some of this species rendered visible, by being 

 a long lime preserved in spirits, which I have laid before this 

 learned society, it will be found, that the only difference 

 between Forster's animalcule, and the medusa scintillans, is 

 in the appearance of the opaque parts, shown in tho micro- 

 scopic views. 

 Luminou'jness Many writers have ascribed the light of the sea to othjer 

 neouslv a>:ci b- causes than luminous animals. Martin supposed it to be 

 eti lo various occasioned by putrefaction : Silberschlag believed it to be 

 phosphoric; professor J. Mayer conjectured, that the sur- 

 face of the sea imbibed light, which it afterward discharged. 

 Bajon and Genlil thought the light of the sea was electric, 

 because it was excited by friction. Forstcr conceived, that 

 it was sometimes electric, sometimes caused from putrefac- 

 tion, and at others by the presence of living animals. Fouge- 

 roux de Bondaroy believed, that it came sometimes from 

 electric fires, but mure frequently from the putrefaction. of 

 marine animals and plants. 



I shall not trespass on the time of the Society, to 

 refute the above speculations ; their authors have left 

 them unsupported by either arguments or experiments, and 

 they are inconsistent with all ascertained facts upon this 

 subject. 



(To be condiidedin_qurM^ff.J,,^^^^^^^^^.';^'.f^ 



HI. Note 



causes. 



