1 8 E. H. HARPER. 



ments, as their discrimination diminishes and random movements 

 begin again when this is the case. 



It is shown that the reactions which are typical of the life in 

 the burrow are more definite and controlled by weaker stimuli 

 than reactions in the open, and this may be expressed by saying 

 that the earthworm's organization is more highly adapted for life 

 in the burrow. Reactions in the axial direction are definite and 

 more sensitive to stimuli than lateral movements in response to 

 light. 



The genus Pcrichceta is noted for its agility, and of its special 

 reactions the leaping movements are the most notable. 



DESCRIPTION OF THE SPECIES. 



Perichata, the eel- worm, as it is called by gardeners, is an 

 exotic genus of earthworms which is said to be quite commonly 

 established in greenhouses in the old world, and also in gardens 

 in parts of France, where they have been introduced, it is said, 

 from the east. The only mention of Pcrichceta having been 

 found in this country, that has come under the writer's notice, is 

 that of Garman, who reported a species of Pcrichatta as becom- 

 ing established in greenhouses in Urbana, 111. The writer found 

 Pcrichceta bermudensis (Beddard) in a greenhouse in Evanston, 

 111. In suitable conditions of soil these worms flourish in great 

 abundance. 



The genus Pcricliceta is noted for its activity. The squirming 

 movements which have given it its name of eel-worm are a strik- 

 ing exhibition of agility. This sort of movement is not confined 

 to Pericliceta, but is developed in the genus to an extent not 

 found elsewhere. By alternate contractions of the longitudinal 

 muscle bands it makes a series of leaps, by which it may waltz 

 about for quite a distance. It reacts in this way when handled 

 or disturbed, as when uncovered from its burrow. 



The worms are of rather large size. They are found often 

 measuring nine inches in lengh when killed fully extended. 

 They are rather pointed at both ends. The continuous circles of 

 setae on each segment give the name to the family. The clitel- 

 lum is a complete band or girdle encircling segments 1416. A 

 large pair of spermiducal glands shine through the opalescent 



