DIPTEBA. 65 



In order to examine the interior cavity, Reaumur opened some 

 of these tumors, either with a razor or a pair of scissors. He 

 found it in a most disgusting state. The larva is lodged in a 

 regular festering wound, matter occupying the bottom of the 

 cavity, and the head of the worm is continually, or almost con- 

 tinually, plunged in this liquid. " It is most likely very well off 

 there," says Reaumur, and he adds that this matter appears to be 

 the sole food of the larva. 



" The position of a horned beast," observes the great naturalist, 

 " which has thirty or forty of these bumps on its back, would be a 

 very cruel one, and a terrible state of suffering if his flesh were 

 continually mangled by thirty or forty large worms. But it is 

 probable they cause no suffering, or at least very little, to the 

 large animal." " Besides," continues Reaumur, " those cattle whose 

 bodies are the most covered with bumps, not only show no signs 

 of pain, but it does not appear that they are prejudicial to them 

 in any way." 



Reaumur tried to discover how the larva, when arrived at its 

 full growth, succeeds in leaving its abode, as the opening is 

 smaller than its own body. 



" Nature," says Reaumur, " has taught this worm the surest, 

 the gentlest, and the most simple of methods, the one to which 

 surgeons often have recourse to hold wounds open, or to enlarge 

 them. They press tents into a wound they wish to enlarge. 

 Two or three days before the worm wishes to come out, it com- 

 mences to make use of its posterior part as a tent,, to increase 

 the size of the exit from its habitation. It thrusts it into the 

 hole and draws it out again many times in the course of two or 

 three days, and the oftener this is repeated, the longer it is able to 

 retain its posterior end in the opening, as the hole becomes larger. 

 On the day preceding that on which the worm is to come out, 

 the posterior part is to be found almost continually in the hole. 

 At last, it comes out backwards and falls to the ground, when it 

 gets under a stone, or buries itself in the turf; remaining quiet 

 and preparing for its last transformation. Its skin hardens, 

 the rings disappear, and it becomes black. Thenceforth the 

 insect is detached from the outer skin, which forms a cocoon or 

 box. At the front and upper part of the cocoon is a triangular 



