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and the anterior half of the back of a common skate, the following 
parts at once come into view :— 
1st. The dorsal aspect of the branchial chambers. 
Qnd. A band of tubes filled with crystalline jelly (a bundle of the 
muciferous tubes of Savi), running from a centre, external to the 
gills, inwards, and a little backwards, but a little way behind the 
temporal orifice. 
3rd. A muscle arising from the cartilage close to the posterior 
branchial arch, but nearer the middle line, and running forwards 
underneath the bundle of tubes just mentioned, to terminate ina 
long, delicate tendon, passing to the extremity of the snout. 
If this bundle of tubes be raised, and drawn forwards, and the little 
fleshy belly of the snout-muscle drawn outwards, in the angle formed 
between them will be found the organ sought for; but probably it may 
remain invisible until a drop or two of tolerably strong acetic acid being 
brought in contact with it, it is thus revealed as distinct from the ge- 
latinous tissue which surrounds it. Thus brought into view, we find a 
little mass, varying in length from ? of an inch to 13 inches, wedged in 
between the occipital muscles internally, and the branchie and their thin 
muscular coverings externally, covered superficially by the tubes and 
snout-muscle, already mentioned, and dipping downwards so as to reach 
the nerve-branches of the vagus going to the gills. 
Viewed with the naked eye, this mass seems to consist of a number 
of quadrangular and pentangular bodies of somewhat irregular form and 
size, united together by areolar texture, and packed beside one another 
in a vertical position. Seen in the microscope, it is found to be composed 
of granular, nucleated substance, and larger cells of a peculiar character, 
seemingly more or less immediately connected with the nervous ramifi- 
cations, the whole entangled in a very abundant areolar tissue. But itis 
to the nerves of this little body that I wish to direct special attention : 
its small size makes it at once obvious that its supply of nerves cannot 
be very large; yet, on careful dissection of large skates, I have found that 
it gets minute nerve-twigs from the branches of the vagus supplying the 
gills, and that it also receives a larger and more easily discovered branch 
from the fifth, which, on close examination, proves to be closely related 
to that which constitutes the first electric nerve of the torpedo. 
Thus, as I have satisfied myself by dissection, as well as from Savi’s 
beautiful plate and description, that the posterior branch of the fifth pair 
in the torpedo, passing out from the cranium, immediately behind the 
temporal orifice, divides into four branches :— 
1. For the muciferous tube system (of Savi). 
2. For the mucous membrane of the mouth. 
8. For the muscles of the jaws. 
4, For the electric organ. 
The same nerve in the skate, also to be discovered just behind the 
temporal orifice, gives off, immediately after escaping from the cranial 
cavity, similar branches, supplymg— 
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