250 LApril, 



I witnessed, and I think I shall show that Reaumur's statement (which 

 always seemed dubious) as to the protection of the eggs by the parent 

 moth must have originated in some mistake. 



If my paper seems long, it must be that I have not power to 

 communicate to the reader the intense interest I myself felt whilst 

 watching the proceedings which I have now attempted to record. 



About the middle of June, 1S76, Mr. Jeffrey sent me larvae in 

 cases made from Myosotis ccespitosa and Potamogcton nutans ; later in 

 the month several from Hydrocliaris morsus-rance and Sparganium 

 simplex, this latter plant abounding with cases in one locality ; in 

 August came cases from Catabrosa aquatica, and in September small 

 larvae of the next generation in cases from Potamogeton polygonifolius 

 and P. pusillus. Meanwhile I had been searching in my own neigh- 

 bourhood, and found a pond with plenty of Potamogeton nutans in it, 

 and on examining the plants round its margin, detected cases cut from 

 most of those mentioned above, and some also from Alisma plantago. 

 It soon appeared, also, that the larvae sent to me on Hydrocliaris, a 

 plant not to be obtained here, made no difficulty in taking to any of 

 the others, as well as to Nymplicea alba ; and, in fine, that whatever 

 might be the food on which the larvae were found, they were quite as 

 well pleased with that which was most convenient for me to give them ; 

 showing themselves, as far as aquatic plants go, thoroughly polypliagous. 



I now give the details of a case-making, which I watched through- 

 out. The naked larva crawled to near the tip of a leaf of Potamogeton 

 natans, fixed its anal legs near the side, and began to eat a little curved 

 channel from the edge through the leaf, working from right to left, its 

 head and body bending round to the left more and more until three- 

 fourths of the intended cut had been accomplished ; then, still keeping 

 the same foothold, it ate back again from left to right, clearing out 

 and widening the channel : next it changed its foothold across the 

 channel to the fixed part of the leaf, whence, stretching out its head, 

 it continued eating from right to left, and so carried on the curve of 

 the channel quite up to the edge of the leaf again, leaving only a very 

 narrow isthmus uncut ; then, as before, it ate backwards to widen the 

 last cut part of the channel ; finally crossing over the channel again, 

 and taking its position on the now almost detached piece, it ate away 

 the last connecting morsel at the very edge, and was adrift as upon a 

 raft : I noticed, however, that a change of plan took place between 

 the first and second parts of its work ; the cut made from the first 

 foothold on the side of the leaf had a long oval curve ; when, however, 

 crossing the channel, the larva continued its work from its foothold on 



