parial

— In the vertebral embryo the first appearance of the parts of the skeleton, in gristle or bone, is a segmental one ; in fishes the muscular system shows much, and in all Vertebrates a little, of the like seo-mental constitution of the trunk : the same idea is suggested by the symmetrical and parial origins of the nerves, and physiologists have mentally recognised a corresponding segmental condition of the myelon or spinal chord, which is visibly exemplified in certain fishes.