OF MYRIAPODA AND MACROURQUS ARACHISfiDA. 
265 
Valentin* on the same animal, and afterwards repeated by Dr. Baly and myself in 
1840-^; and lastly, whether the seat of sensation and volition is confined entirely to 
the supra-oesophageal ganglia, the brain, in these Articulata. 
No experiments have yet been made on any of the Myriapoda with reference to 
these inquiries, save only one, imperfectly described by Duges^; ; hence it has become 
especially necessary that, with this object, our inquiries should be extended to these 
lower forms of life, so far removed from those on which experiments have already been 
made, and in which, from their low organization, the phenomena may be well studied. 
With this object I have made experiments on one of the lowest of the Chilognatha, 
Lulas terrestris, and on one of the highest of the Chilopoda, Lithobius forjicatus. 
The questions that seemed necessary to be examined, were — 
1st. Whether sensation and volition are confined to the supra-oesophageal ganglia, 
the brain, or whether they exist also in the first suboesophageal ganglion, or in the 
other ganglia of the cord ? 
2nd. Whether these functions are destroyed by partial destruction of the brain ? 
3rd. Whether there is any direct evidence of sensation in a portion of the cord that 
is insulated from the brain? 
4. Whether the movements in these animals, when deprived of the brain, are iden- 
tical with those of the Crustacea and Vertebrata ? 
lulus terrestris. 
Experiment 1 . — The front of the head, antennae, eyes, and brain were at once re- 
moved with a pair of scissors from an active adult specimen. While held between 
my fingers there were powerful contortions of the whole body of the animal, and when 
placed on a table it moved rapidly forwards, as in the usual mode of locomotion, and 
continued to do so for a few minutes, but the motions gradually became slower and 
slower, and at last were so feeble that onward progression was suspended, although 
the legs were still feebly moved, as in walking, for nearly half an hour, when their 
motions entirely ceased. There was no evidence whatever of sensation or volition, 
although the suboesophageal ganglion and cord were uninjured. During locomotion 
the body moved in a direct line, and always forwards. When it met with a slight 
obstacle it climbed over it, or when too high to pass over, the body stood directly 
opposed to it, with the mutilated portion of the head in contact with the obstacle, 
and the locomotive actions of the limbs gradually increased, apparently by the excite- 
ment of contact with a foreign body against the lacerated surface of the head. When 
the movements of the limbs ceased, the body was maintained in its natural position 
upon them for several hours, until fresh mechanical excitement was applied to it, 
when the locomotive actions were repeated. 
* De Function. Nervorum, Bern. 1839. (Vide Baly’s Muller.) 
t Muller’s Physiology by Dr. Baly, second edition, vol. i. 1840, p. 771. 
J Traite de Physiologie Comparee, tom. i. p. 162. 
