368 SUPPLEMENT 



That in whatever gas these glow-worms ma}/ have been, the 

 light has never appeared to be augmented. 



That this light is produced by small luminous bodies, 

 which the insect can cover with a membrane. 



That after having removed these luminous points from the 

 body of the insect, without endangering it, it has continued 

 to live, but without any re-appearance of light. 



That these luminous points, removed from the living insect, 

 and exposed to the action of many gases, have produced light 

 there for different spaces of time, from which this author seems 

 to conclude tliat the duration is greater in the oxygen gas than 

 in the others. 



The experiments made by Dr. Carradori on the lampyris 

 Italica^ have furnished him with the following results : — 



These insects shine at will, in each point of their abdomen, 

 which proves that they possess the faculty of moving all the 

 parts of this viscus, independently one of the other. 



They can render their phosphorescence more or less lively, 

 and prolong it for as long a time as they think proper. 



The faculty of shining does not cease in consequence of the 

 laceration, or incision of the abdomen. 



M. Carradori has seen a part of the abdomen separated 

 from the rest of the body, which had been almost extinct, 

 become all at once luminous for some seconds, and after- 

 wards be extinguished insensibly. Sometimes he has beheld 

 a similar portion cut off, pass suddenly from the finest bril- 

 liancy into a total extinction, and afterwards resume its 

 former light. M. Carradori attributes this phenomenon to a 

 remnant of irritability, or a stimulus produced by the air. 



A slight compression is sufficient to deprive the lampyrides 

 of the faculty of shining. 



The phosphoric matter once expressed loses in a few hours 

 all its splendour, and is converted into a white and dry 

 substance. A piece of the phosphoric abdomen, put into 



