DESCRIPTION OF A MODEL SHOWING THE TRACTS 

 OF FIBRES MEDULLATED IN A NEW-BORN 

 BABY'S BRAIN 



FLORENCE R. SABIN 



From the Anatomical Laboratory of the Johns Hopkins University 



ELEVEN FIGURES 



In 1900 I published a description of a model of the medulla, 

 pons and mid-brain made from a series of sections of the brain 

 stem of a new-born babe.^ 



In this model were shown first the form of the main nuclear 

 masses and secondly, the form of the fibre tracts that had received 

 their medullary sheaths, thus the study was based on the fact 

 that the tracts of the central nervous system are successively 

 medullated, as has been worked out by Flechsig, and was the 

 result of the idea that at birth so few of the tracts have received 

 their medullary sheaths, that it is possible to model them out and 

 obtain a picture of their form. A clear picture of the form of such 

 tracts as the lemniscus medialis and fasciculus longitudinalis 

 medialis, even though it represent only one stage of development 

 is of value from two standpoints, first in pointing the way toward 

 a picture of the tract in the complicated relations of the adult 

 brain, and secondly in leading toward an understanding of the 

 modifications in form of the tracts as they shift in their relations 

 in development. 



1 Sabin, A Model of the Medulla Oblongata, Pons and Mid-brain of a New-Born 

 Babe. Contributions to the Science of Medicine dedicated by his pupils to William 

 Henry Welch, Johns Hopkins Press, 1900; and Johns Hopkins Hospital Reports, 

 vol. 9; and Atlas of the Medulla and Midbrain, The Friedenwald Company, Balti- 

 more, 1901. 



The American Journai. of Anatomy, Vol. 11, No. 2 



