TUBE-MAKERS. 333 



If a glass jar containing this Amphitrite (as he 

 calls it) be emptied and replenished with sea-water, 

 Sir J. G. Dalyell says that the animal will retreat, 

 the orifice of the tube be closed, and all 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 

 passing spectator would conclude that he now 

 beholds only a beautiful flower, completely ex- 

 panded, 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, disturb- 

 ing its purity, then, while the plume unfolds to its 

 utmost capacity, does the animal commence a slow 

 revolution, the body also passing round within the 

 tube. Now are the thousands of cilia fringing the 

 ribs of the branchiae discovered to be in vigorous 

 activity, and their office to be wondrous. A loose 

 muddy mass is soon afterwards visibly accumu- 

 lating in the bottom of the funnel ; meantime the 

 neck, or first segment of the body, rising unusu- 

 ally 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 collections 



