REFLEX ACTIONS OF ARTICULATA. 



259 



of its body all the evidences of perfect volition. It moved actively along, 

 turning itself back on either side repeatedly, as if to examine the anterior 

 wounded portion, which it felt again and again with its antennas: and when 

 attempting to escape, frequently turned back as if in pain and aware of some 

 hindrance to its movements ; but it seemed perfectly unconscious of the 

 existence of the posterior part of its body, behind the first incision. In those 

 segments, in which the cord was destroyed, the legs were motionless ; while 

 those of the posterior division, behind the second incision, were in constant 

 but involuntary motion, the movements being similar to those of walking or 

 running, uniformly continued, but without any consentaneous action with 

 those of the anterior part, by which locomotion was performed, dragging the 

 posterior divisions of the body after them. When the animal was held by 

 the posterior segments, reflex actions were excited in the legs, and powerful 

 contractions and gyrations of the whole animal were performed in those seg- 

 ments; but these movements appeared to be entirely the result of reflex 

 actions of the muscles, since exactly similar ones took place in the whole 

 body of decapitated specimens. At the expiration of twelve hours, the most 

 perfectly voluntary acts were performed by the head and anterior division of 



* 



Fig. 128. 



Parts of Nervous System of Articulata. A. single ganglion of Centipede, much enlarged, showing the 

 distinctness of the purely fibrous tract, b. from the ganglionic column, a. B, portion of the double cord 

 from thorax of Pupa of Sphinx ligustri, showing the respiratory ganglia and nerves, between the gan- 

 glia (2, 3, 4), and the separated cords of the symmetrical system, c, view of two systems combined, 

 showing- their arrangement in the Larva ; a, ganglion of ventral column ; b, fibrous tract passing over 

 it 5 cc, respiratory system of nerves distinct from both. 



the body, such as locomotion forwards or to either side, avoidance of any 

 obstacle, touching it with the antenna?, (which were in rapid action, as in an 

 uninjured animal,) and attempting to reach and to climb up an object pre- 



