The Hunting Wasps 



affecting the whole of the motor organism. 

 Without a prolonged struggle, which might 

 be fatal to the patient, without repeated 

 operations, which, if too numerous, might 

 jeopardize the Beetle's life, the Wasp has, 

 if possible, to suppress all power of move- 

 ment at one blow. It Is essential therefore 

 that she should aim her sting at the nervous 

 centres, the seat of the motor faculties, 

 whence radiate the nerves scattered over the 

 several organs of movement. Now these 

 sources of locomotion, these nervous centres, 

 consist of a certain number of nuclei or 

 ganglia, more numerous in the larva, less 

 numerous In the perfect Insect and arranged 

 along the median line of the lower surface in 

 a string of beads more or less distant one 

 from the other and connected by a double 

 ribbon of the nerve-substance. In all the 

 insects in the perfect state, the so-called 

 thoracic ganglia, that Is to say, those which 

 supply nerves to the wings and legs and go- 

 vern their movements, are three In number. 

 These are the points to be struck. If their 

 action can be destroyed, no matter how, the 

 power of movement will be destroyed like- 

 wise. 



There are two methods of reaching these 

 48 



