18 NOTES ON 
vessels, running the whole length of the larva, 
have their origin in the head, and the ramifica- 
tion commences near the eyes. Throughout 
the animal a peristaltic motion is perceptible ; 
its interlor appears to be one large canal, hav- 
ing the vessels running along each side of it; 
the tail consists of nine strong bristles, each 
tapering to a point; they are transparent, and, 
when viewed under a deep magnifier, appear 
like hollow tubes, without strie or markings of 
any kind. The animal has the power of clos- 
ing all these bristles into a bundle, and, from 
the instantaneous manner in which this is ac- 
complished, casual observers have supposed 
them sheathed within the last segment of the 
body. 
As general microscopic objects, few will be 
found to afford more amusement; placed in an 
aquatic live-box, with a sprig of moss or con- 
ferve, they form an entertaining spectacle, 
entwining themselves among the moss, and 
darting about in various directions, withdraw- 
ing and spreading out the tail, &c. If put in 
the same aquatic slider with the larva of a 
Dytiscus, the latter may be seen in pursuit of 
them, and destroying all within its reach. 
They seldom require more amplification than 
