392 



that conclusions drawn from the relative weight of the brain 

 and of the body are open to many objections ; as the weight 

 of the latter must be influenced by the previous state of health, 

 of fulness or of emaciation ; the weight of the brain too must 

 be materially affected by the amount of fluid it contains, or 

 which may have escaped during the operations of removal and 

 of weighing. Attention to the relative structure of the brain, 

 therefore, is also necessary. The convolutions of the elephant's 

 cerebrum are very numerous, but rather small, and but few of 

 the sulci are deep ; the fissure of Sylvius is closed, and there- 

 fore that numerous group of convolutions forming the "island 

 of Reil" are absent ; the grey neurine is not so thick as in 

 man : on the whole, the cerebrum bears more analogy to that 

 of the porpoise than to that of man, in whom the convolu- 

 tions are large and numerous, the sulci deep, and many of 

 them involuted over and over again. In man, too, the fissure 

 of Sylvius is very deep, and when opened out presents a pro- 

 digious number of convolutions ; his posterior cerebral lobes 

 are extensive, and overlap the cerebellum ; the grey neurine 

 forms a thick investing lamina, the superficial extent of which 

 is increased to a wonderful extent, and to a degree superior to 

 what it is in any other animal. 



" I shall next place before this meeting a dissection of the 

 proboscis or trunk of the elephant, the organ which forms 

 the striking and characteristic feature of this group of ani- 

 mals, no other possessing it in a perfect state, though in 

 many it is rudimentary, as in the tapir and in the pig. It 

 is essential to the existence of this animal, as the instrument 

 for taking its food, and hence its name (ttjoo, jSoo-kw). Its 

 length varies from four to six feet, according to the height of 

 the animal ; it is of a conical form, the base is attached to the 

 nose, of which it may be regarded as a continuation, and is 

 about two feet in circumference ; the apex is from four to six 

 inches ; the fore-part and sides are convex, and marked by 

 rugged, transverse folds, which admit of extension and change 

 of form ; the posterior surface is flat and rough, and bounded 



