Mr. Brightwell on Filarie and Insects. 397 
increase, an increase which has been sometimes so great in stagnant 
waters, as to change them into the appearance of blood, and make them 
like a thick mass of living water. 
The Daphnie are about the size of a pin’s head, and half a dozen 
Tipulidan larve will clear a bottle well stocked with them ina few 
hours. They seize their prey with the rapacity of a Pike, grasping it 
with the two anterior jaws or hooks (as Reaumur calls them) and gorging 
it alive. The larger Daphnia, filled with ova, often struggle a long 
time in the jaws of their adversary, who can only swallow them by 
degrees. These darve will live several days without food, but die after 
that time, although the water be daily changed. Once, being unable to 
‘procure any Daphnie, I cut some roasted mutton into small particles, 
and on putting a few into the bottle in which I kept the darve, most of 
them struck at, and two actually gorged, this substantial diet. One of 
these I kept for some days in a small glass tube, watching it carefully 
until the mutton had digested. From the transparency of the animal 
this process might distinctly be perceived ; the food dissolving into an 
opaque fluid, was gradually absorbed by the surrounding vessels, until 
the body was tinged with a greenish color. This animal continued in a 
highly vigorous state for two days without any other food, when it 
changed first into the nympha state, then into a fine specimen of the 
perfect insect. 
A bad figure of this larva is given by Reaumur; we have given a 
more accurate one, Plate XIX., fig. 1, in which a. is the animal of the 
natural size and b, highly magnified. In the latter the parts as described 
by Reaumur will be readily traced. 
II, Most Naturalists are aware of the fact that intestinal worms are 
found in the bodies of various insects, and particularly in those of several 
species of the Carabide inhabiting moist situations. I have found them 
most abundantly in the bodies of the Harpalus or Molops madidus, a 
very common insect of this family. These worms, which are identical 
with, or allied to, the Gordius aquaticus, Linn, (Filaria of modern 
authors), are a most formidable foe to these insects, devouring the 
