xxvi Journal of Comparative Neurology. 



lutely no metameric value of its own. Its nerves cannot be used as 

 criteria to metamerism, at least not directly, as general cutaneous 

 nerves may. This applies to the author's discussion of the post-otic 

 branchial nerves as well. The use of the peripheral nervous system 

 as a criterion of metamerism is always attended with difficulty and it is 

 absolutely worthless in this connection unless the qualitative differences 

 in the nerves themselves are taken into consideration. c. j. h. 



Miss Sabin's Model of the Medulla Oblongata.^ 



Although the preparation of Miss Sabin's models has brought out 

 comparatively few facts which are actually new to science, neverthe- 

 less it must be regarded as a notable feature of current neurological 

 progress. This is the first time that the spatial relations of the internal 

 organs of the medulla oblongata and adjacent parts have been pre- 

 sented m three dimensions with anything like completeness. The descrip- 

 tions and figures which Miss Sabin gives of her models are of great 

 value to all teachers and students of morphology. We should like to 

 see reproductions of the models themselves put upon the market. 



c. J. H. 

 Schaper on the Elements of the Selachian Retina.^ 



The facts which Dr. Schaper brings out in this beautifully illus- 

 trated Uttle paper are interesting chiefly because they picture the ele- 

 ments of the retina as seen in surface preparations made with methy- 

 lene blue intra vitam and thus permit a comparison of the results of 

 this method with the study of the same subjects by Golgi's method 

 made by Retzius and Neumayer. His results, as was to have been 

 expected, while not contradicting theirs, nevertheless supplement them 

 in many particulars and add to our knowledge of the inter-relations of 

 these elements. No neurites were discovered for the amakrine cells of 

 the inner granular layer, but the so-called bipolar cells of that layer 

 have short axis cylinder processes all directed centripeially and appar- 

 ently terminating in the inner plexiform layer. Anastomoses were not 

 observed between any of the retinal elements. This work emphasizes 

 again the necessity for abundant control of both the Golgi and methy- 

 lene blue methods. Successful methylene blue preparations in general 

 seem to give a more complete impregnation of the ultimate termini of 

 the cell processes than the Golgi method can furnish, though probably 

 requiring more skill and experience for their true interpretation. 



c. J. H. 



^ A Model of the Medulla Oblongata, Pons and Midbrain of a New-born 

 Babe. By Florence R. Sabin. In Contributions to the Science of Medicine, 

 dedicated by his Pupils to William Henry Welch on the 25th Anniversary of 

 his Doctorate. Johns Hopkins Press, Baltimore, 1900, pp. 925-1046, with 8, 

 plates and 52 text-figures. 



^ Die nervosen Elemente der Selachier- Retina in MethylenblauprHparaten, 

 by Dr. Alfred Schaper. Festschr. fur v, Kupffer,Jena., 1899. 



