INSECTS IN COMMERCE 145 



in the pseudo-chrysalis state. After its long 

 rest the insect once more casts its skin and 

 becomes an active larva. It no longer feeds, 

 however, but spends a few days burrowing about 

 in the ground ; it then changes into a true pupa, 

 and after another short period of rest reappears 

 transformed into a bright, active little beetle 

 about four-fifths of an inch in length and of a 

 beautiful green colour. 



The particular species of Cantharidae used 

 for making ointment and blisters are natives of 

 Spain, hence their popular name of Spanish fly. 

 They are found principally on the ash, lilac, 

 privet, and elder trees, on which they swarm at 

 times in great numbers, betraying their presence 

 by the strong, pungent odour they emit, which 

 can be detected quite a long way off. 



The beetles are collected very early in the 

 morning when they are torpid from the cold 

 night air ; cloths are spread at the foot of the trees 

 on which they are congregated, and the branches 

 vigorously shaken to dislodge them. The cloths 

 are then gathered up by the four corners and 

 plunged bodily into a solution of hot vinegar; 

 after this the Cantharides are thoroughly dried 

 and packed in air-tight vessels. Great care has to 

 be taken in collecting and preparing the beetles 

 that they do not come in contact with the skin, 

 as so powerful is the vesicant fluid they emit 

 that it raises very painful blisters. 



Cantharides were employed in the art of 

 healing at a very early date. Hippocrates is 

 said to have administered it internally as a cure 

 for dropsy, apoplexy, and jaundice, and Aretaeus, 



