Abstract
In my previous papers on the ‘Electric Organ of the Skate,’ I considered the develop­ment of the organ in Raia batis the structure of the organ in R. circularis , and the structure and development of the organ in R. radiata . I propose now to consider the relations, structure, and progressive growth of the organ in R. batis , to contrast the organ of R. batis with that of Torpedo , and to refer to the various modi­fications of the electric organ I have found in the Skate genus.