PECULIAR SECRETIONS. 369 
they consisted of perpendicular hollow columns, reaching 
from the ventral to the dorsal surface of the animal; and, 
where the organ is thickest, extending to an inch and a 
half in length; and where thinnest, to one-fourth of an 
inch. These columns he found to be four, five, and even 
six-sided ; but Mr Tod is inelined to consider them cylindri- 
cal*. The coats of the columns are thin and transparent, 
closely connected with each other, by a'loose network of ten- 
dinous fibres, passing transversely and obliquely between 
the columns. They are, likewise, attached by strong ine- 
lastic fibres, which pass directly from one column to ano- 
ther. The cavity of each column is divided into a num- 
ber of cells, (containing a fluid which M. Gxorrroy found 
composed of albumen and gelatine), by transverse partitions, 
which, in a column of one inch, amount to 150. These 
partitions consist of a very thin translucent membrane ; 
their edges appear to be attached to one another, and they 
are connected to the inside of the columns by a fine cellu- 
lar membrane. The whole organ is covered by a thin mem- 
brane, composed of fibres running in a longitudinal direc- 
tion, and united to the skin, or sutrcunding parts of the 
body, by a cellular substance. Within this external mem- 
brane of the electrical organ, there is another, consisting 
likewise of fibres, running, however, in a transverse direc- 
tion. The sides of the columns take their rise from this 
membrane. The arteries by which the electrical organs are 
nourished, after penetrating the investing membrane, ra- 
mify upon the sides of the columns, and send in, to the 
partitions, numerous small branches, which anastomose with 
one another, and with the vessels of the adjacent partitions. 

* Phil. Trans. 1816, p. 121. 
