HYDJROCAMPA NYMPH^ATA. 89 



and their food were transferred for a few minutes 

 from the large china bowl in which they were kept to 

 a saucer of water, and while here it happened, on 

 three occasions, that pellets of frass were ejected 

 with some force out of the water, to the distance of 

 eight inches beyond the saucer, on the table ; its 

 propulsion seemed frequently to be in an upward 

 direction, as I constantly noticed latterly a large pro- 

 portion of frass adhering to the side of the bowl two 

 inches or more above the water. 



After feeding well for ten days, during which time 

 all the five leaves of the plant sent with them had 

 become much ravaged and reduced to fragments, to my 

 great satisfaction the larvse appeared on the 16th of 

 the month to have ceased feeding ; and towards 

 evening 1 was greatly surprised to see the smaller 

 larva had abandoned its case, and was crawling naked 

 over the remains of its food-plant, its colour a little 

 faded ; on the morning of the 17th I found it half out 

 of the water, on the side of the bowl; in the afternoon 

 I saw, with much perplexity, the larger larva had also 

 left its case, and was crawling about through the 

 water in a forlorn condition, and much paler than 

 before. I now had great anxiety for their ultimate 

 fate, as their behaviour did not seem to agree with 

 their alleged habit of pupating within their cases, 

 which were still as fresh-looking as at first; so, with 

 a faint hope of their spinning up amongst the debris 

 of their food, I left them for the night. The next 

 morning, seeing both larvse out of the water, and 

 looking very miserable, it struck me that they were 

 seeking some other kind of plant to make up in, and 

 I supplied some Gallitriche verna and Helosciadium 

 nodiflorum, but on neither of these plants would they 

 stay, and I then tried some pieces of Sparganium 

 ramosum, on which they crawled about and lingered 

 some time, which induced me to obtain several longer 

 pieces, and to stand them upright, with the lower ends 

 in water, within a glass globe, and after placing the 



