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E. A. ANDREWS. 



tached by the posterior end and feel about like a leech and later 

 swim off in a short arc to settle again. When carmine grains 

 were added to the water it was evident that the animal was 

 attached by the posterior end to an invisible film or raft of 

 secretion that formed a pellicle over the surface of the water and 

 extended out irregularly in all directions to a distance of one 

 to four times the length of the Folliculina. 



These thin pellicles that moved on the water with the contract- 

 tions of the Folliculina were probably made by the individual 

 animals from secretions of an adhesive nature and if other Fol- 

 liculina had come near they might have had their motions in- 

 fluenced by this secretion so that they would have tended to 

 settle down in the same neighborhood and so on till many 

 individuals might become crowded together in one region and 

 have all made their cases together as seen in Figs. 6, 3, and 4. 



1.05 



1.08 



1. 10 



FIG. 7. Sketch of four successive groupings of motile forms that are settling 

 down to form cases. Drawn at intervals of a few minutes from 1.05 to i.io p. m. 



That several active Folliculina may be influenced to act to- 

 gether in one region is shown by the observations illustrated in 

 Fig. 7. Here four motile forms attracted to the same spot 

 remained for a long time with rapid changes of form and position 

 within the group but did not move away from one another's 

 company. Sketched at 1.05 o'clock, the four were radiating 



