270 
MR. NEWPORT ON THE NERVOUS AND CIRCULATORY SYSTEMS 
position and remained with its legs widely extended. When quiet, progressive motions 
were instantly induced by touching the cut end of the cord, or by pressure on the an- 
terior segment. When pressure was made over the posterior caudal ganglion, violent 
contortions of the whole body were induced, as in lulus. The antennse were completely 
paralyzed and draggedalong the sides, and compression of them produced no retrac- 
tion, or any movements of the body or legs. But contortions of the whole body were 
produced by compression of the mandibles, or of the posterior pairs of legs. When a 
brisk current of air was passed from a blowpipe along the sides of the body on the 
stigmata, no motions were induced in the legs until after a few seconds, and then 
they were regular but slight. A brisk knock on the table always re-excited the 
movements. At the expiration of half an hour the antennal subsegment was re- 
moved, leaving the medulla in situ. Progression was again induced, but more feebly 
than before. When pressure was applied on any of the segments the reflected move- 
ments were as violent as at first. The mandibles were now fixed, but contortions of 
the whole body were induced when these were pinched. These contortions were most 
violent when pressure was applied over the great subcesophageal ganglion, the medulla, 
but occurred also when the cut extremities of the crura were irritated with a needle. 
Experiment 13. — The left antenna and side of the brain were removed together. 
The results were very similar to those in lulus (experiments 6 and 7)- The volition of 
the animal was greatly impaired, but when the remaining antenna was touched the 
animal gave full evidence of sensation by instantly retracting it, and when it was 
pinched the whole body was violently contorted. It was also frequently drawn be- 
tween the closed mandibles, as if to cleanse it from anything adhering to it, as is the 
usual habit of this species. This was evidently the result of sensation, but not perhaps 
an act of volition, since in all other respects the movements most certainly were reflex. 
The movements were usually to the left, or injured side, but not invariably. At the 
expiration of half an hour the cord was divided between the fourth and fifth pairs of 
legs. Excessively violent movements were now induced, but w T hen placed on its back 
the animal did not regain its natural position. Pressure on any of the segments pro- 
duced motions of the jaws, as in the act of biting, but without any direction, conse- 
quently these were reflex. The cord was then divided between the seventh and eighth 
pairs of legs. The reflex movements of progression were now more imperfect, but 
continued longest in the anterior portion of the body. Powerful contortions were as 
readily excited in the posterior part as before, but these contortions were confined to 
the posterior half ; since none were excited in the insulated portion of cord between 
the fifth and ninth pairs of legs, except on firm pressure of the ganglia. When the 
animal was placed on its back the motions to recover its position were feeble and 
ineffectual, and almost entirely ceased without the body recovering its natural posi- 
tion. But motions were instantly re-excited when pressure was made over any of the 
ganglia; and the limbs, both anterior and posterior to the ganglion pressed on, 
were thrown into violent actions on both sides of the body, exactly as in the original 
