538 D. L. GAMBLE 



The interpretation most generally accepted is that of Goeppert 

 ('96), who attempted to show that the attachment of the rib to 

 the neural arch has come about in a complicated fashion. Goep- 

 pert was an advocate of the view that the rib is an outgrowth of 

 the basal stump, while Rabl thought of the same structure as an 

 independent element, having nothing to do genetically with the 

 vertebra. Goeppert therefore offered another explanation to 

 account for the new rib attachment, which was not incompatible 

 with his behef in the morphological relations of the two structures. 



The following is a brief summary of Goeppert 's work on this 

 problem. In Necturus, the basal stump, at about the middle 

 of its length, sends off a dorsal process which he called the 'rib- 



Fig. 1 A series of diagrams to illustrate Goeppert's interpretation of the 

 change in the vertebral attachment of the rib in urodeles. Black, rib-bearer; 

 stippled, parapophysis (basal stump of Goeppert); clear, rib; b, basal portion of 

 basal stump; b-d, distal portion of same; n.a., neural arch; n.c, notochord. 

 A, Necturus; B, Salamandra; C, Triton. 



bearer' (fig. lA, black). This passes dorsally to the neural arch, 

 laterad of the vertebral artery, and then continues dorsocaudally 

 over the surface of the arch. The rib-bearer is separated from 

 the cartilage of the neural arch by a sheath of connective tissue 

 and later bone. Laterad of the rib-bearer the basal stump (fig. 

 lA, stippled) continues horizontally, and the rib (fig. lA, clear) 

 forms as a mere prolongation of this element. Further laterad 

 still the rib develops a dorsal process which extends mesally 

 toward the vertebra and becomes the dorsal head of the rib. 



In the larval Salamandra, according to Goeppert, the basal 

 portion of the basal stump has disappeared, and its place is taken 

 by a slender bar of bone (fig. IB, b). The distal end of the basal 

 stump (fig. IB, b-d), that is, the portion which projects laterad 



