V 

 THE NERVOUS SYSTEM 



BRAIN AND SPINAL CORD 



1. Historical. 



Funk, in his general monograph (1827), describes the external fea- 

 tures of the brain, but his figures are poor. In 1890 Oyarzun pub- 

 lished some account of the histology of the fore-brain, and a year 

 later Burckhardt gave a very good account of the brains of Triton 

 and Ichthyophis. His work has been used as a basis by most subse- 

 quent investigators of the brains of Urodeles. In 1897 Gehuchten 

 discusses the habenular ganglia and commissure. Bochenek (1899) 

 and Rubaschin (i 903) add contributions to the histology of the fore- 

 brain, whilst more recently Rothig (191 1—27) has made a vary care- 

 ful and extensive study of the constitution of the several parts of the 

 brain of a number of Urodeles, including Salamandra. Driiner 

 (1901) gives excellent figures of the brain of Salamandra, both larval 

 and adult, in his paper on the muscles and nerves of the hyobranchial 

 apparatus, but he does not describe them. 



Some five workers have made a special study of the pituitary body, 

 or hypophysis cerebri. The first of these was Haller (1896). His 

 work is very good, and he recognizes that the infundibular portion 

 undergoes considerable atrophy, but fails to differentiate more than 

 one region in the hypophysial part. He was followed by Bochenek 

 (1902), who, working with Golgi's neurological methods, concen- 

 trated on the distribution of the fibre tracts within the infundibulum. 

 Haller returned to the subject with a larger comparative account in 

 1909, but it was not until 1921 that a complete description of the 

 hypophysis was given by Atwell, while three years later a confirma- 

 tory account was published by Sumi (1924). 



The present account deals only with the general structure and 

 external features, including the main commissures and cavities visible 

 in a median sagittal section. The works above referred to, and others 

 of a more general nature included in the bibliography, must be con- 

 sulted if further details are required. 



2. Membranes of the Brain and Spinal Cord. 



Our knowledge of the membranes investing the brain and spinal 

 cord in Urodeles is still far from being adequate. Some account of 



