Scientific Intelligence.— Comparative Anatomy. 221 
taken at Boucherville, a distance of 9 miles from town. It was 
exhibited at Montreal, then towed down for exhibition to Que- 
bec. This animal must have come from the Whale Bank off 
Newfoundland, which is the nearest place where whales are ge- 
nerally found, and have wandered at least I GOO miles in a 
straight line up the gulf and river before it was taken, 350 or 
400 miles of which must have been fresh water. 
COMPARATIVE ANATOMY. 
21. Structure of Electric Organs of Gymnotus elect ricus.— 
On each side there is an upper large and an under small elec- 
tric organ. The large organ arises immediately behind the 
head, under the great dorsal muscles, where it is obtuse, and 
gradually becomes narrower, and terminates acutely towards the 
end of the tail. It is straight, or somewhat hollowed, towards 
the back-bone, but convex in the opposite direction : above, it 
terminates in a line ; in a nearly similar manner below, and is 
thickest in the middle. It is composed of horizontal plates, 
about the third of a line from each other, which are traversed 
at right angles by partition walls, and in the small space be- 
tween them water is contained. Below this large organ lies a 
similar, but smaller and more minutely divided one. These 
parts are supplied with numerous intercostal nerves : in the 
specimen examined by Hudolphi, 224 were observed on each 
side. A great branch of the third branch of the fifth pair of 
nerves, augmented by a smaller branch from the vagus, runs 
parallel with the back-bone, from the head to the tail, where it 
divides. This nerve runs immediately over the intercostal 
nerves, and crosses them at right angles, without, however, unit- 
ing with them in any way; on the contrary, they are entirely 
distributed to the muscles of the back. This is the nerve which 
Hunter describes as the vagus, and which Fahlberg erroneous- 
ly considered as the electric nerves; while Hunter, with his 
usual accuracy, describes the intercostal nerves as those of the 
electric organs. If we compare the electric organs of the tor- 
pedo and gymnotus electricus, the first may be compared with 
the voltaic pile, the second with the trough apparatus. But 
they agree in their principal feature, viz. in the abundant dis- 
tribution of nerves to very vascular plates, between which a se- 
rous fluid is disposed. 
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