OF THE EARTHWORM. 129 



the presence of numerous small worms. . . . The 

 phenomenon was so curious that I took up some 

 of these worms and carried them into the house to 

 examine them by the light of my lamp. I imme- 

 diately recognized them to be small Lumbrics, 

 about fifteen millimetres long. Returning again 

 into my garden, with a lantern, I saw at the same 

 place many Lumbrics crawling upon the ground 

 with their usual slow and regular mode of progres- 

 sion. But they showed no light ; and when the 

 lantern was put out, their presence could not be 

 recognized. But as soon as they were in their 

 turn sprinkled with warm urine, the phosphores- 

 cence of their entire bodies shone forth and illu- 

 minated their wriggling movements." 



The writer of this letter says he has since re- 

 peated the experiment many times, and he asks 

 if the phenomenon ought to be attributed to the 

 saline matter contained in the urine, or if the 

 warmth of this liquid is alone necessary to oc- 

 casion the phosphorescence of Lumbrics. This 

 might have been easily ascertained by using pure 

 warm water in the experiment; but the author 

 of the letter apparently did not think of it. His 

 observation, as we have given it in his own words, 

 tends to prove that violent muscular contraction 

 excites an increase of phosphorescence in the 

 earthworm as in the Noctiluca mentioned among 

 animals in the preceding chapter; and the fact 



K 



