88 Jounial of Comparative Neurology and Psychology. 



The nerves were clipped within the vertebral canal and the 

 brain and spinal cord were removed unseparated, with the dura 

 mater intact except that of the ventral surface of the brain* 

 The whole was placed in io% formalin which was renewed on 

 the following day. No measurements were made till after the 

 material had .been in this fluid for several months and, unfor- 

 tunately, no weights were taken in the fresh condition. At 

 the time the study began some weighings and measurements 

 were made of the formalin material. Since the two specimens 

 proved to be quite similar, the following record for one of them 

 will serve for both: 



Length ot entire nervous system .... 



Length of spinal cord from tip of calamus scriptorius 

 to end of conus medullaris ..... 



Lateral diameters of spinal cord: 



1st segment, near calamus scriptorius 

 8th segment 

 17th segment, 

 22nd segment, 

 32nd segment, 

 42nd segment. 

 Weight of brain and spinal cord with dura except 



that of basal surface of brain 

 Weight of brain severed at tip of calamus 



scriptorius ....... 



Weight of spinal cord from tip of calamus 



scriptorius to end of conus medullaris 

 Weight, of lumbar region, 28th to 38th 



segments inclusive ..... 



Owing to the action of the formalin upon^the tissue, the 

 weights must be regarded as ranging somewhat higher than 

 the fresh material would have given. They may be considered 

 as approximate however, and as indicating the relations be- 

 tween the part-. In every case the pieces were dried on blot- 

 ting paper for a given length of time before weighing. 



It will be noted ( i ) that the cord is quite slender, being 

 about twice as long as that of man; (2 ) that the cord is rela- 

 tively nearly twice as heavy as the brain, and ( 3 ) the great 

 size of the lumbar enlargement, it being nearly one-third the 

 weight of the brain, and measurements show it to have more 

 than twice the diameter of any other region of the cord. 



96.5 centimeters. 



90. 



8. millimeters 



5 

 6 



69.5 grams. 



26.1 



43-3 



9.2 



