612 



ON THE CEREBRAL HEMISPHERES OF RODENTS. [DeC. G, 



(6) Owen, Sir R. — 'Comparative Anatomy and Physiology of 



Vertebrates.' 



(7) Flower, Sir W. H. — " Oii the Structure and Affinities of the 



Musk-Deer (Moschus moschiferus, Liun.)," P. Z. S. 1875, 

 p. 159. 



(8) Leurep, F., & Gratiolet, P. — 'Anatomic comparee du 



Systeme nerveux.' Paris, 1839-18.57. 



(9) Alston, E. R.— " On the Classification of the Order Glires," 



P.Z. S. 1876, p. 61. 



P.S. (December 29th, 1892). — I am indebted to the kindness 

 ol Prof. Howes for the opportunity of figuring (fig. 7) and 

 describing a most remarkable Rabbit's brain. The animal was 



Fig. 7. 



Brain of Eabbit, showing abnormal deTelopment of convolutions. 



a domesticated Rabbit, and was dissected in the laboratory of the 

 Royal College of Science by one of Prof. Howes's students. Ordi- 

 narily the brain of this Rodent has but one slightly marked furrow 

 upon the upper surface of each hemisphere, which corresponds to 

 that lettered a in the series of woodcuts which illustrate this pajjcr. 

 In the brain before me this furrow is present, but it is continuous 

 from one end of the brain to the other, having a somewhat zigzag 

 course ; at the angles formed by the zigzags of furrow a a number 

 of transverse furrows are given off, which for the most part reach 

 the under surface of the cerebrum joining the rhinal fissure. In 

 addition to tlie^e (of which one seems to correspond to the Sylvian 



