THE EVIDENCE OF THE SKELETON
The bony and cartilaginous skeleton considered, not the notochord--
Nature of the earliest cartilaginous skeleton--The mesosomatic
skeleton of Ammocoetes; its topographical arrangement, its
structure, its origin in muco-cartilage--The prosomatic skeleton of
Ammocoetes; the trabeculæ and parachordals, their structure, their
origin in white fibrous tissue--The mesosomatic skeleton of Limulus
compared with that of Ammocoetes; similarity of position, of
structure, of origin in muco-cartilage--The prosomatic skeleton of
Limulus; the entosternite, or plastron, compared with the trabeculæ
of Ammocoetes; similarity of position, of structure, of origin in
fibrous tissue--Summary 119