CORRELATION BETWEEN METABOLIC GRADIENTS. 335 



TABLE IV Continued. 



invariably negative (galv.) to all other parts and the margin nega- 

 tive to the subumbrella and exumbrella. In Stomotoca the manu- 

 brium and the margin were invariably negative to the exumbrella, 

 and it can be inferred from the table that the manubrium is nega- 

 tive to the margin ; the small size and tall bell-shape of this species 

 did not permit the testing of the subumbrellar surface. In 

 ^Equorca the electric conditions are somewhat dependent upon the 

 sexual condition. This medusa has numerous radial canals which 

 bear the gonads on their subumbrellar surfaces, as is the case in all 

 of the Leptomedusse ; the canals are so numerous that it is impos- 

 sible to avoid touching the gonads on applying the electrodes to the 

 subumbrellar surface. In sexually ripe individuals the negativity 

 of the subumbrellar surface is increased and it may be negative 



