DEVELOPMENT OF THE LIMBS, BODY-^^'ALL AND BACK 



IN MAN. 



CHARLES RUSSELL BARDEEN, M. D. AND WARREN HARMON LEWIS, M. D. 

 From tlm Aiiatomical Laboratory of the Johns Hopkins University, Baltimore, 31(1. 



With 9 Plates and 27 Text Figukes. 



The purpose of the following paper is a description of various typical 

 stages in the development of the back, the limbs, and the body-wall 

 in man. The work is based primarily upon reconstructions, according 

 to the method of Born,' of parts of five human embryos; it has been 

 extended and controlled by a study of the external form and of serial 

 sections of several other human embryos. Dr. Lewis has devoted special 

 study to the formation of the arm. Dr. Bardeen to that of the leg, the 

 body-wall and the back. 



In the accompanying table a list is given of the embryos utilized. 

 Those marked with an asterisk have been reconstructed. 



We shall consider the early stages in the development of the limbs, the 

 body-wall and the back, first, from the point of view of the external 

 form and, secondly, from that of internal structural differentiation. 



I. External Form. 



The external form of the embryos we have used has been compared 

 with that of embryos of a corresponding stage of development pictured 

 ^-- XI, „ TT-:^ A+inc.2 T^io-o ^-^^ on naffes 3 to 9 represent a series of 



ERRATUM FOR Vol. I, No. 1. 



Vol. I, No. 1, page 83, Fig. 2, of this Journal should read: 



Fig. 2. Embryo of 13.0 mm. Sagittal series, No. 224, section 6.5. x 30 diams. 



