98 L October, 



tion ; being almost colourless, and keeping well under water when 

 moving from plant to plant, these larvae were very hard to watch, but I 

 was fortunately able to see one on its travels within twenty-four hours 

 of hatching, and noted that it was about -h inch long, and that the 

 food had begun to darken its internal vessels : in twelve days' time, 

 August ISth, I saw another larva, now i inch long ; on the 2Gth, 

 noticing that one of the oldest pieces of Sparganium seemed deserted, 

 being well riddled with mines through its length, as well as pierced by 

 numerous little holes in the rind, through which the larvae had entered 

 at first, I isolated it in a saucer of water, and watched to see if any 

 larvae would still come out of it, for their transparency rendered it 

 almost impossible to make sure of their presence or absence by holding 

 the plant up to the light ; after a few hours, three larvae appeared, now 

 grown to i inch in length ; and by pursuing a similar course with 

 other pieces of Sparganium as they became brown, I got a sight of ten 

 larvae by the end of the month. On September 11th, I detected a larva 

 now over f inch long, and turned it into a saucer of water without 

 food in order to secure a figure of it ; on the 2Sth, I observed another 

 now ^ inch long, and noticed that there was no colour down the back 

 arising from food within ; this 1 took as a hint Ihat it had ceased 

 feeding and was preparing to hibernate, and on examining other pieces of 

 Sparganium I discovered several larvae already laid up, quite colourless, 

 and quite torpid : unfortunately, these investigations could be effected 

 only at the cost of killing the larvae examined, for I found they soon 

 died after their rest had been broken. 



However, by the beginning of October, I had established a large 

 cylindrical glass jar, in which several fine plants of Sparganium 

 simplex were growing, no longer floating but erect and robust ; upon 

 these, were placed some of the less torpid larvae about an inch or two 

 beneath the water, and I had the satisfaction of seeeing them mine 

 their way into the plants until they were out of sight ; the rest still 

 occupjnng pieces of Sparganium Avere introduced among the growing 

 plants to take their chance. 



The winter proved open and favourable for the experiment, and 

 in due course the plants turned brown and died down naturally, 

 collapsing and sinking at last to the bottom of the water ; but by the 

 middle of February, 1S77, a few very thin and tender narrow shoots 

 began to appear again ; after this, a thick growth of Conferva, which 

 at first I did not like to meddle with, greatly impeded my view, till on 

 the Gth April I cleared some of it away, and removed some worms I 

 found feeding on the debris of the old plants, and a few other crea- 



