[April, 
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 w hich I have now r attempted to record. 
About the middle of June, 1876, Mr. Jeffrey sent me larvae in 
cases ma( ^ e from Hyosotis ccespitosa and Potamogeton natans ; later in 
the month several from Hydrocharis morsus-rancs and Sparganium 
simplex , this latter plant abounding with cases in one locality ; in 
August came cases from Catabrosa aquatica, and in September small 
lanae of the next generation in cases from Potamogeton polygonifolius 
and P. pusillus. Meanwhile I had been searching in my own neigh- 
bom hood, and found a pond with plenty of Potamogeton natans in it, 
and on examining the plants round its margin, detected cases cut from 
mofet of those mentioned above, and some also from Alisma jplantago. 
It soon appeared, also, that the larvae sent to me on Hydro char is, a 
plant not to be obtained here, made no difficulty in taking to any of 
the others, as well as to Nymphcea alba ; and, in fine, that whatever 
might be the food on which the larvae were found, they w^ere quite as 
w ell pleased with that which w r as most convenient for me to give them ; 
show ing themselves, as far as aquatic plants go, thoroughly polyphagous. 
I now gi\ e the details of a case-making, w r hicli 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, 
ciossing the channel, the larva continued its work from its foothold on 
