Chap. XL] UNCONSCIOUS COGNITION. 159 



powerful arms terminating with hooks, with which it is 

 accustomed to seize and pierce its prey. When the head 

 together with this first thoracic segment was excised, the 

 hody of the Insect, supported on its four remaining legs, 

 resisted attempts made to overturn it, and at the same 

 time agitated its wings and wing-cases. When, after this, 

 the head was detached from the first thoracic segment, the 

 latter single and isolated body segment afterwards showed 

 signs of life by the continuance of ' reflex actions ' of a pur- 

 posive character for more than an hour. When touched, 

 it moved its arms, turning them towards the finger of the 

 experimenter, and even nipping it strongly. 



These were actions of much the same kind as would 

 have been exhibited towards a Fly or other prey, if the 

 segment had formed part of an entire Mantis. In such a 

 case, the movements would, doubtless, have been, to some 

 extent, consciously instigated through the Brain of the 

 animal. The above-mentioned experiment, however, shows 

 conclusively that the movements of the arms and claws 

 which were seen when the thoracic segment was severed 

 from the head, must have been executed through the inter- 

 vention of the single bilobed ganglion, together with the 

 afferent and eff'erent nerves which the segment contains. 



Dr. Carpenter says:* " If the head of a Centipede be 

 cut off whilst it is in motion, the body will continue to 

 move onwards by the action of its legs ; and the same will 

 take place in the separate parts, if the body be divided 

 into several distinct portions. After these actions have 

 come to an end, they may be excited again by irritating 

 any part of the nerve centres, or the cut extremity of the 

 nervous cord. The body is mo^ed forwards by the regular 

 and successive action of the legs, as in the natural 

 state ; but its movements are always forwards, never 

 * " Mental Physiology," 3rd Edition, p. 53. 



