COLEOPTERA. 493 
We come now to the tribe of blistering beetles, of which the 
best known is the Cantharides (Cantharis or Lytta). These 

Fig. 540.—Blaps obtusa. Fig. 541.—Tenebrio molitor 
(larva and imago). 
insects are generally of soft consistency, and their elytra very 
flexible. A few remain constantly on trees. All are very brisk 
and active. When swallowed they are a dangerous poison, but 
are used in medicine for making blisters. 
The Cantharides of commerce (Cantharis (Lytta) vesicatoria) 
are of a beautiful green, attain to a size of four-fifths of an inch,- 
and are found on ash trees, lilacs, and other shrubs: Commerce for 
a long time brought them from Spain, and some still come from 
that country; hence the common name of Spanish fly. As they 
live in great numbers together, collecting them is easier and less 
expensive than would be that of other species of the same family 
which are not gregarious, but which have the same medicinal 
properties. The presence of the Cantharides is manifested by the 
strong penetrating odour which they diffuse to some distance. 
When, by aid of this smell, they are discovered, generally settled 
on an ash, they are collected in the following manner :—Very 
early in the morning a cloth of light tissue is stretched out at the 
foot of the tree, and the branches are shaken, which causes the 
insects to fall. These, numbed by the cold of the night, do not 
try to escape. When there is a sufficient quantity, the four 
corners are drawn up and the whole plunged into a tub of 
vinegar diluted with water. This immersion causes the death 
of the insects. They then carry them to a loft, or under a very 
airy shed. To dry them they spread them out on hurdles covered 
with linen or paper, and from time to time, to facilitate the 
