THE COLEOPHOKA, OR TENT-MAKERS. 35 



tliat arrangement of muscular fibre, by which the systole and 

 diastole is maintained? and would the peristaltic motion, so 

 necessary to digestion, go on without that exquisite network 

 of innumerable muscular threads, which twine along, and 

 across, and around every internal organ ? No ; all this 

 mystery of life goes on planned, directed, and sustained 

 beneath the tegument of this microscopic worm. 



" Now what is the little larva about? 1 have placed it 

 under the microsco})e ; it has at length entered the leaf, and 

 eaten more than the length and breadth of its body. I 

 turned it out of its case at 2 p.m. It wandered restlessly 

 until 4 P.M., then fixed and opened its circular door, slowly 

 going forward, until on my return at 10 p.m. it had advanced 

 into perfect shelter. The next morning a large blotch was 

 eaten, but I was in time to sit beside the elm-branch and 

 watch the making of the tent. It had fixed near the edge 

 of the leaf, and was carefully eating out the jjarenchyma of 

 each serrature, leaving the edges untouched, as it thereby 

 saved a seam in the tent, yet emptying each tooth to make 

 it light and less brittle. When all was clear, the larva 

 measured a gentle curve a little larger than its body, and 

 began to draw the cuticle together on the opposite side to 

 the serratures— tacking it loosely at first, and biting the 

 membrane between the fibres, sewing it more neatly then, 

 and careful not to cut the supporting braces formed by the 

 nerves of the leaf Then it rubbed the interior of the case 

 with its head, as if to smooth it, and presently began to 

 darken it with a web of fine silk, rendering further operations 

 invisible, only I perceived that one end was left open for 

 the ejection of its excrement, and that the fibres were cut 

 mysteriously away, when the tent by powerful muscular 

 action was raised from the leaf, and the Coleophora marched 

 off to refresh itself in a new excavation. Yet that was another 

 point on which to rest and ponder. What was it eating, and 

 how much did it eat? What store of delicate ami varied 

 food lies in the cells of any leaf; sugar and starch and chlora- 

 phyll, oils and gums and raj)hides ; ay, and in some plants, 

 like the common nettle, beautitid crystals suspended from the 



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