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III. On the Brain and other parts of the Hippopotamus (H. amphibius). 

 By A. H. Gabrod, M.A., F.R.S., Prosector to the Society. 



Eeceived and read June 17, 1879. 



[Plates III. & IV.] 



The male Hippopotamus from the Upper Nile, presented to the Society by the late 

 Viceroy of Egypt on the 25th of May, 1850, died on the 11th of March, 1878, without 

 any serious disease of any organ, but after having suffered for some years from ulcers 

 on the legs, which were much more inflamed during the winter- than the summer- 

 seasons ; because then the comparative coldness of its tank did not allow of its remaining 

 in the water for any length of time, and the cutaneous surface became dry as well as 

 cracked. 



The animal was about thirty years old, and apparently aged. From the front of the 

 nose to the base of the tail it measured 1 2 feet along the back, the tail being 22 inches 

 long. 



In his monograph on the anatomy of Hippopotamus amphibius^ Professor Gratiolet 

 has fully described and figured the brain of the new-born animal. Nevertheless there 

 is a want of definiteness about the delineation of the convolutions, and a difference in 

 the proportionate size of the cei'ebellum, which makes me feel justified in asking the 

 Society to grant me opportunities for giving illustrations of the brain of the adult ani- 

 mal. The necessity for a second figure is increased by the peculiarities in an outline 

 sketch of the brain of Hippopotamus liberiensis given by Prof. Macalister in his account 

 of that species-. 



In a valuable monograph on the brain of the Ungulata ^, recently published. Dr. 

 Julius Kreug has introduced views and adopted a nomenclature which every student of 

 the nervous system cannot help finding of particular service in any special investigation 

 like the present. By an extensive comparison of the convolutions of individuals at dif- 

 ferent ages, and of different species. Dr. Kreug has arrived at a standard of which are 

 fundamental aud which secondary sulci, that has enabled him to represent what is the 

 typical arraugement of the surface of the hemispheres in the Ungulata generally. 



' ' Recherches sur ranatomie de 1' Hippopotame,' Paris, 1867. 



° Proceedings of the Royal Irish Academy, vol. i. series 2, Session 1873-74, plato xxviii. 



' ' Zeitschrif fc f iir wisaenschaftliche Zoologie,' Leipzig, 1878, pp. 297-344, 



c2 



