1898.] MICROSCOPICAL JOURNAL 173 



Some Observations on Brain Anatomy and Brain Tumors. 



Dr. William C. Krauss, of Buffalo, read a paper at the 

 92nd annual meeting of the Medical Society of the State 

 of New Yort, Albany, Jan. 25, 1898, with the above title. 



He called attention to the difficulty in remembering the 

 gross anatomy of the brain, and to the almost universal 

 presence of optic neuritis in cases of brain tumor. He 

 attempted to overcome the difficulty in regard to the 

 anatomy of the brain by formulating the following rule.-s, 

 which are somewhat unique aud original, and at the same 

 time easily remembered. 



The nerve centres are divided into two great divisions 

 encephalon, and myelon. The encephalon is divided into 

 two subdivisions, cerebrum, and cerebellum. The cere- 

 brum, cerebellum and myelon are divided into two hem- 

 ispheres each, right, and left. The- encephalon is in- 

 dented by two great fissures, longitudinal and transverse. 

 Into these two great fissures there dip two folds of the 

 dura, falx cerebri and tentorium cerebelli. There are two 

 varieties of brain matter, white and gray. 



There are three layers of membranes surrounding the 

 brain, dura, arachnoid, pia. Each hemisphere is indented 

 by three major fissures, sylvian, rolandic or central, 

 parieto-occipital. Three lobes, frontal, temporal and oc- 

 cipital, on their convex surface are divided into three 

 convolutions each, — superior, middle and inferior. There 

 are three pairs of basal ganglia, striata, thalami, quadri- 

 gemina. The hemispheres of the brain are connected by 

 three commissures, anterior, medi, post-commissure. 

 The cerebellum consists of three portions, right, and left 

 hemisphere, vermes. There are three pairs of cerebellar 

 peduncles, superior, middle, inierior. The number of 

 pairs of cranial nerves, in the classifications of Willis 

 and Sommering, can be determined by adding 3 to the 



