288 
POPULAR SCIENCE REVIEW. 
such as those of the Ephemeridce and Perlidce. We notice, 
too, numerous habitations of the larvaB of the Phi'yganeidw or 
caddis-flies. On the present occasion, let us confine our atten- 
tion to these last-named insects. 
The insects belonging to the family of Phryganeidoi (order 
Trichoptera of some entomologists) derive their name from the 
Greek word 4>pvyavov, a faggot,” or dry stick,” in allusion 
to the bits of stick of which the larvae very frequently make their 
habitations. This method of constructing their cases, in which 
the larvae and nymphae reside, appears to have been noticed as 
early as Aristotle, who says: “There is a small worm-like 
creature, called Xylophthorus ; its variegated head extends be- 
yond its case, its feet are at the upper extremity, as in other 
worms ; the rest of the body is contained in a case made of a 
substance like a spider’s web, around and outside of which are 
chips of wood, so that the animal walks about with this attached 
to it. These creatures are attached to their cases as an oyster 
to its shell ; the whole of the case is joined to the worm, and 
does not fall out of it, but can be drawn out, as if they grew 
together. If anyone pulls off the case the animal dies, and 
becomes as helpless as a snail without its shell. As time 
advances this worm becomes a chrysalis like a caterpillar, and 
lies without motion ; but the nature of the winged creature that 
is produced from it has not been ascertained.” * 
This family has b*een studied by De Geer, who entered some- 
what minutely into the details and structure of the insects 
belonging to it ; but he did not succeed in tracing more than 
five species through their different states. He has given figures 
of a variety of cases, including several perfect insects. Eeau- 
mur and Eosel have also given drawings and descriptions of a 
few species with their transformations ; but nearly all the insects 
of the group whose larvae these authors have figured belong to 
one genus alone, that of Phryganea, Passing over the names of 
other naturalists, whose researches have helped to throw light 
on the history of the Phryganeidce^ we come to that of M. 
Pictet, whose valuable memoir “ Eecherches pour servir a 
I’histoire et a I’anatomie des Phryganides,” has been spoken of 
as being “ one of the most perfect monographs ever published.” 
M. Pictet has published other valuable memoirs on the Ephe- 
meridce and Perlidce, two families belonging to the order 
Neuroptera. This naturalist detected about 120 species of 
Phryganeidce in Switzerland alone, and noticed the preparatory 
states of not fewer than fifty- two, only seven in their early 
stages having been previously observed by De Geer. 
Professor Westwood gives the following characteristics of the 
An./’ v. 26, § 2. 
