672 ON SOME EXPEHIMKNTS WITH DRAGONFLY LABViE, 



These three larvae were supplied with a jar full of mosquito 

 larvae (about two or three hundred). As these wriggled past 

 them, they seized and ate with the utmost greed all that they had 

 time to catch. One larva ate over fifty mosquitoes in ten minutes, 

 t)ut after that refused to eat any more until the next day. These 

 larvae are now in one of my large aquaria; are feeding well and 

 appear to be nearly full-fed; but T do not now expect them to 

 -emerge until next November. 



The remaining larva was again returned to his place under the 

 middle rock*. The tank was then left without observation for 

 just over five weeks, i.e., until Sunday, May 1st. On lifting the 

 middle rock on that date, I found that the larva had de.serted his 

 old haunt. I examined the other rocks, and found him buried 

 flat under one of them, so I carefully replaced the rock upon him. 

 I was quite unable to find any other larvaj, though I knew that 

 there should be three or four more somewhere. 



Another month was now allowed to pass. On May 29th I 

 again lifted the rock under which J had left the larva. It was 

 still there, but appeared somewhat shrivelled and inert. Fearing 

 that it had about reached the limit of endurance, and desiring to 

 preserve it and breed it out at a later date, I now removed it and 

 dropped it into an aquarium. Tt revived at once, swam to the 

 bottom, and began a vigorous onslaught on the mcsquito-larvse 

 with which I supplied it. It is to-day alive in the aquarium and 

 feeding well. 



Regarding the experiment now as practically ended, I removed 

 and examined all the rocks. I found no larvae under any of 

 them. I then took a watering-pot and watered the sand all over 

 until it was soaked completely through. In a few minutes 

 bubbles appeared in various places, and there crawled out two 

 or three specimens of a small dark centipede, several small red 

 worms of a kind I have often seen in fresh-water ponds, 'Aud/our 



* This larva was kept in a small box of dry sand from Friday, April 25th, 

 to Wednesday, April 30th, and was exhibited on the latter date at the meet- 

 ing of the Linnean Society. Vide Proceedings antea, p.48. 



