WORMS. 205 



The only use that has yet been made of Lum- 

 liricus terrestris, or the common earth-worm, of 

 which there are many varieties, is that of baiting 

 the hooks and nets of fishermen. The large varie- 

 ties that crawl upon the damp grass at night, living 

 during the day in the earth, are captured in large 

 quantities by poachers, etc., for baiting night-lines. 

 In the same manner marine worms are used by the 

 fishermen of seaport towns. 



and is known at present as Filaria piscium. But this F. piscium, 

 being always deprived of sexual organs, M. Joly looks upon it as 

 the larva which, in the body of the seal, completes its development, 

 and becomes F. Cordis phocoe. 



Entozoa possess a wonderful tenacity of life. They have been 

 known to revive after being placed for half an hour in boiling water. 

 They have likewise been seen to survive the cold produced by ice ; 

 and they have been brought to life again after having lain in a dry 

 state for six or seven years. They live in the most extraordinary 

 places. In certain tropical climates there exists a species of rattle- 

 snake, which, in Cumana, enters into the houses to catch mice. In 

 the abdomen and in the large pulmonary cells of this reptile, a five- 

 mouthed worm, Pentastoma, has been discovered. Another species 

 of Pentastoma is found in the bladder of frogs. Ascaris lumbrici, a 

 little spotted worm, the smallest of all species of Ascaris, has been 

 discovered under the skin of our common earth-worm (Lwmbricus 

 terrestris), furnishing us with an example of a worm living upon a 

 worm. Leucophora nodulata is a very minute worm, of a silvery 

 or pearly aspect, living in the body of the small red worm, Na'is 

 littoralis, of our river banks, and constitutes another example. 

 These few notes will, I hope, show what peculiar interest attaches to 

 this numerous and curiously diffused tribe of beings, and it is with 

 much impatience that I await the forthcoming work of a truly able ob- 

 server, Dr. T. Spencer Cobbold, upon this class of animals. Pouchet 

 in his Heterogenie energetically denies their wonderful migrations. 



