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tures which I regarded as water vermin ; and then I could see clearly 

 quite a tangled growth o£ young and very tender leaves of the Sparga- 

 nium low in the water ; some of them in a few days reached the surface 

 and lay floating there, and the first evidence I had of the larvae begin- 

 ning to feed occurred on April 20th, when I detected a small fragment 

 of a leaf floating on the surface, and near it a kind of green dust, 

 which, by help of a magnifier, I made out to be frass ; at length I 

 detected the whereabouts of the larva hidden between two young 

 leaves, which at the place seemed spun together just beneath the 

 surface of the water ; three days later I saw other similar appearances, 

 and for the first time after hibernation saw a larva very distinctly in 

 the act of feeding ; its position was nearly vertical between two leaves, 

 just at the point where after rising about an inch above the water 

 they bent down again to float on it, here it had spun the leaves to- 

 gether with silken threads, but had left a little opening through which 

 I could watch it leisurely eating the edge of the lower leaf ; more 

 than half its body was above water, the remainder obscured by the 

 lacing to and fro of the silk threads ; this larva seemed to be \ inch 

 long or perhaps more, and paler than when feeding in autumn, but 

 otherwise similar ; next day, it had cut the leaves asunder at that part, 

 and ensconced itself in a fresh residence lower down the plant under 

 water, probably unable to tie the walls of its previous abode completely 

 together, from the circumstance of another individual having firmly 

 secured itself between the floating extremities of the same two leaves. 

 Onwards from day to day I could distinguish the positions of others 

 just beneath the surface, and some quite low down in the water, with 

 minute air bubbles clinjriii": to some of their abodes. 



They now began to greatly ravage the plants, pieces cut from the 

 the tips of the leaves and other portions being often found floating on 

 the surface. Occasionally, I })artly opened some of their residences to 

 obtain a peep at the inmates, and found them steadily growing ; one 

 of these tenements I cut off on the 27th April, and placed it in a 

 saucer of water to take a figure of it ; it had been constructed by 

 drawing the two edges of a leaf partly towards each other for the 

 length of nearly an inch, and by joining to them with a spinning of 

 silk some parts of two other adjacent leaves, on both of which the larva 

 had fed occasionally, advancing its head for this purpose as far as it 

 chose ; while my attention was engaged on its appearance, I saw five 

 little pellets of frass suddenly ejected from it, which convinced me the 

 occupant was in a proper state for examination, so I proceeded to pull 

 the construction to pieces, and to expose the larva which now measured 



