1892.] Physiology. 1051 
PHYSIOLOGY. 
The Functions of the Nervous System of the Myriapoda. 
—The following experiments on the nervous system of the Myriapoda 
were begun with the intention of continuing them upon some of the 
other Paviedabentie, for the purpose of comparing the ditferent 
relations. It has been impossible thus far to fulfil this plan, and 
therefore these results are given rather as preliminary than as com- 
plete in themselves. 
The animal used in the experiments was the common species 
(Lithobius), and it proved a rather unfavorable subject. But the 
large Iulide, which would doubtless have been better, could not be 
obtained. The Lithobius is very active and quick in its motions, so 
that it was necessary to perform some of the operations while the 
animal was under the influence of chloroform. After the operation in 
most cases, some time, varying from an hour or two, to a day, accord- 
ing to the nature of the experiment, was allowed to pass before obser- 
vations were made, this allowing recovery from the shock and from 
the irritation of the wound. 
The method of experiment was as follows: a portion of the nervous 
system was removed or isolated from the rest, or destroyed by a cut or 
by burning with a loop of very fine platinum wire heated red-hot in 
an electric circuit. After recovery from the immediate effects of the 
operation the actions of the animal were observed at intervals until its 
death. The same operations were again and again repeated, so that 
the results given represent the observations of a large number of 
individual cases. 
The supercesophageal ganglion consists essentially of a small 
whitish mass just beneath the dorsal surface of the anterior segment, 
sending out two lobes transversely, which end in the nerves leading to 
the eyes, and just beneath these two other lobes extending forward, 
and giving off the nerves which pass into the antenne. This ganglion 
is connected with the ventral cord by two rather thick commissures, 
which form a very small esophageal ring. The ventral cord is practi- 
cally the same in structure throughout its whole length, being a double 
cord connecting a series of ganglia corresponding to the segments of 
the body. 
The operations upon the supercesophageal ganglion were performed 
either by removing the head or some part of the ganglion by a cut, or 
