How Animals Work. 



left the following account : " Let a tall and ample 

 crystal jar containing a Sabella be emptied of its con- 

 tents and speedily replenished with sea water : the 

 animal, if in view, has retreated during the short in- 

 terval ; the orifice of the tube is closed ; all is at rest. 

 But soon after replenishment it rises, to display its 

 branchial plume still more vigorously than before, 

 and remains stationary, as if enjoying the freshness of 

 the renovated element, always so grateful the har- 

 binger of health and strength to those whose dwelling 

 'is there. The passing spectator would conclude that 

 he now beholds only a beautiful flower, completely 

 expanded, inclining towards the light like some of 

 those ornaments of nature decorating our gardens. 

 He pauses in admiration. But if a drop of liquid mud 

 falls amidst the element from above, disturbing its 

 purity, then, while the plume unfolds to its utmost 

 capacity, does the animal commence a slow revolution, 

 the body also passing around within the tube. Now are 

 the thousands of cilia fringing the ribs of the branchiae 

 (plumes) discovered to be in vigorous activity, and 

 their office to be wondrgus. A loose muddy mags 

 is seen afterwards visibly accumulating in the bottom 

 of the funnel ; meantime the neck, or first segment of 

 the body, rising unusually high above the orifice of 

 the tube, exhibits two trowels beating down the thin 

 edge as they fold and clasp over the margin, like our 

 fingers pressing a flattened cake against the palm of 

 the hand.* During these operations muddy collec- 

 tions are seen descending between the roots of the fans 



' The trowels are the lappets of the collar encircling the base 

 of the plumes. 



4 6 



