312 



TORPEDO RAY. 



appears to be common to all sizes in the same state 

 of humidity, for by drying they may be greatly 

 altered; whence it appears probable that the in- 

 crease in the length of a column, during the growth 

 of the animal, does not enlarge the distance be- 

 tween each partition in proportion to the growth ; 

 but that new partitions are formed and added to 

 the extremity of the column from the fascia. The 

 partitions are very vascular ; the arteries are 

 branches from the veins of the gills, which convey 

 the blood that has received the influence of respira- 

 tion. They pass along with the nerves to the 

 electric organ, and enter with them : then ramify, 

 in every direction, into innumerable small branches 

 upon the sides of the columns, sending in from the 

 circumference all around upon each partition small 

 arteries, which ramify and anastomose upon it ; 

 and passing also from one partition to another, 

 anastomose with the vessels of the adjacent parti- 

 tions. The veins of the electric organ pass out, 

 close to the nerves, and run between the gills, to 

 the auricle of the heart. The nerves inserted into 

 each electric organ, arise by three very large trunks 

 from the lateral and posterior part of the brain. 

 The first of these, in its passage outwards, turns 

 round a cartilage of the cranium, and sends a few 

 branches to the first gill, and. to the anterior part 

 of the head, and then passes into the organ towards 

 its anterior extremity. The second trunk enters 

 the gills between the first and second openings, 

 and after furnishing it with small branches, passes 

 into the organ near its middle. The third trunk. 



