82 
INTHOBUCTIOX. 
are most exposed to friction. The little d>velling is 
now complete, but continues attached to the spot 
where it was formed. In order to disengage it, the 
insect puts out the anterior part of its body, and 
fixing its fore-legs to the leaf, drags the case for- 
wards, retaining its hold of it chiefly by the small 
hooks on the abdominal legs. It is now in a con- 
dition to transport itself fr'om one leaf to another, 
and select the portions best suited to its taste, 
without incurring the risk, which it seems so much 
to dread, of exposing itself to the air. 
Apparently with the view of saving themselves 
the labour of sewing up one of the sides of their 
domicile, some of these creatures have the sagacity 
to mine the leaf close to one of the edges, and thus 
preserve the membrane unbroken on three of its 
sides. “ Their proceedings,” says one of the authors 
of the Introduction to Entomology, “ I had the 
pleasure of rritnessing a short time since upon the 
alders in the Hull Botanic Garden. More ingenious 
than their brethren, and willing to save the labour 
of sending up two sides in their dwellings, they 
insinuate themselves near the edge of a leaf instead 
of in its middle. Here they form their excavation, 
mining into the very crenatures between the two 
surfaces of the leaf, which, being joined together 
at the edge, there form one seam of the case ; an<l 
from their dentated figure, give it a very singular 
appearance, not unlike that of some fishes which 
have fins on their backs. The opposite side they 
