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respiration of insects. M. Faivre had attempted to show that the 
respiratory movements depend entirely on the metathoracic ganglion, 
and that the posterior part of the ganglionic chain acts merely asa 
conductor. M. Baudelot has arrived at a very different conclusion: 
he experimented on the larva of the dtagon-fly, and after cutting off 
the head found that for six hours the respiratory movements were 
strong and regular, while even after a lapse of twenty-one hours 
they were apparent, though weak, nor did they cease entirely until 
twenty-seven hours after the operation. Secondly, he bisected a 
specimen immediately behind the metathorax, notwithstanding which 
respiratory movements were continued in the abdominal portion for 
something more than twelve hours, and in one case even for twenty- 
four hours. Moreover, he arrived at similar results in the dragon-fly 
itself, and he concludes therefore that the respiratory movements of 
insects are not, like those of Vertebrata, under the rule of one special 
part of the nervous system, but that each ganglion acts for itself as a 
centre of force. 
Prof. Faivre has also published, in the ‘Annales des Sciences 
Naturelles’ (New Series, vol. i.), some interesting investigations into 
the nervous system of insects. It is hardly necessary for me to re- 
mind the Society that we owe to our great entomologist Newport the 
interesting discovery that the nervous column in Aiticulata consists 
of two parts, an upper band with motor functions, and a lower 
ganglionic cord of sensitive nerve matter. He suggested, moreover, 
that the nerves had a double origin as well as a double function. 
M. Faivre has succeeded in proving by experiment the accuracy of 
these views. After carefully exposing the prothoracic ganglion, he 
found that on irritating the under surface of the ganglion he obtained 
unmistakeable signs of pain, indicated by general movements; while 
irritation of the upper surface merely produced movement in the 
corresponding leg, action on the right side of the ganglion always 
affecting the right leg, that on the left side the left leg. But further 
than this M. Faivre found it possible to isolate the power of motion 
from that of sensation, so as to paralyze either at will without affecting 
the other. If he made a longitudinal section through the upper part 
of the ganglion on the side, the leg on that side lost all power of 
motion. Ifthe insect walked the leg took no part in the movement, 
and if the leg itself was pinched it remained equally motionless. Yet 
its sensibility was unimpaired, and any irritation of it produced reflex 
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