182 ANIMAL PARASITES AND MESSMATES. 



it produces disease (AnguiUulina dipsaci). It attacks 

 the flowers, and remains on them without signs of life 

 till the moment that they are moistened. The vinegar 

 eel is another nematode worm which has some affinity 

 with the preceding ones. It has been considered a 

 Rachitis. 



There exists also a river species; but have not 

 different worms been confounded under this name? 

 Many species live in brackish water, and these are 

 remarkable for the presence of bristles on their heads, 

 and by very distinct eyes. 



