is-r.] 101 



of the plant begins to fade a little : on approaching its full growth, the 

 larva keeps nearer the surface of the water, and sometimes cuts through 

 a leaf all but just the fibre on one side, which causes the upper portion 

 to fall and be suspended in the water ; observing how this was done 

 by a larva in captivity which I had received from Mr. Jeffrey, I was en- 

 abled to find one by seeing a Sparganmm similarly treated in a brook, 

 wiiere, in former years, I had often sought for the larva in vain ; on 

 those occasions, however, I had only sought in on the surface of the 

 water, or above it, seldom or never beneath, expecting, as I did, to find 

 it in a case of some kind, after the manner of its congener nymphcsaUs. 



The eggs, which my friend sent me, in two groups, appeared to 

 number thirty-seven in one group, and forty-nine in the other, laid 

 very close and evenly together in rows, and somewhat imbricated ; in 

 shape, the egg is roundish-ovate, and its surface striated ; the colour, 

 olive-yellow and semi-pellucid, showing the embryo rather paler ; in 

 about a week, they become roundish above, and greyish, and begin to 

 show a black blotch at their summits, and next day the larvae appear. 

 The newly-hatched larva has a blackish head and plate on the second 

 segment, a clear and colourless body, and in twenty-four hours shows a 

 broad, greenish-grey dorsal vessel through the clear skin, the lobes of the 

 head blackish, mouth and ocelli black, being about to inch in length ; 

 when twelve days old, it is in length a trifle more than iinch, the head 

 and plate on second segment changed to very pale brown, the body 

 translucent, of a watery yellowish-green tint, the internal vessel light 

 greenish ; in twenty days, it grows to be a quarter of an inch long, of 

 slender proportion, the third and fourth segments the stoutest, slightly 

 tapering from them each way, the head and second segment light 

 brown, body pale greyish-brown, the intenuil vessel rather deeper 

 greyish-brown, broad at beginning of the third segment, and not 

 visible beyond the ninth, the second segment clear and transparent 

 as the others. 



In another month's time, it is nearly half an inch long, of a light 

 brownish-olive colour, the segmental folds of skin, and its outline 

 showing the most colour, and also the fine tracheal thread; the 

 lobes of the head outlined with darker brown and the mouth darker, 

 ocelli black. When about to hibernate, the body becomes transparent 

 and colourless. 



The full-grown larva measures | inch in length, of rather slender 

 proportion, tapering from the third segment to the head, and again 

 gradually from about the tenth to the anal extremity, the head small, 

 flattened, and tapering towards the mouth, the segmental divisions 



