STITDV OF BRAINS OF SIX EMINENT SCIENTISTS AND SCHOLARS. 259 



mustardseed-like patches of atheroma but iKjthing else unusual. The brain was pre- 

 served in Miiller's fluid and later transferred to alcohol. Casts of the cerebral halves 

 and of the cei-ebeiluin, pons and oblongata (in one piece) were subsequently made 

 under Dr. Dercum's supervision. 



The brain was weighed while fresh, Ijy Dr. Dercuni, with the same scales which 

 Dr. H. Allen employed in weighing the brain of Joseph Leidy. Troy weights were 

 used. The brain-weight of Philip r>eidy, as determined by Dr. Dercum, was 45.5 oz. 

 (Troy) equivalent to 1415 grams. The weights of the encephalic parts on November 

 2, 1904, were as follows : 



Left liemicerebruin ........ 525 grams. 



Right hemicerebruia ....... 522 " 



Cerebellum, pon.s and oblongata 162 " 



Total 1209 grams. 



The loss in weight through the removal of the pia-arachnoid and through the 

 action of the preservatives during the long period of immersion (1891-1904) amounts 

 to 206 grams or 14.5 per cent, of the original weight. 



The Cerejjrum. 



The cerebrum shows a high degree of complexity and richness of fissuration in 

 all its parts. Viewed dorsally the right half appears slightly longer. Except foi' the 

 more prominent fronto-lateral curve and blunter occipital pole on the left side the 

 cerebrum is quite symmetrical in form. Viewed laterally and comparing the two 

 sides, the left preoperculum is seen to be the better developed and, as in the brain of 

 Joseph Leidy, the right sub-parietal areas are much more extensive. Viewed ven- 

 trally the right temporal lobe appears moi-e massive while the left temporal is more 

 richly fissured ; the same comment applies to the appearances of the orbital surfaces. 

 The left semi-circumference is 22.8 cm. ; the right semi-circumference it 23.4 cm. 



Although the callosum in this brain is not as large as that of Joseph Leidy it is 

 of unusual proportions. The callosal length is 8 cm., nearly 1 cm. above the average ; 

 and while the average in ordinary brains is equivalent to less than 42 per cent, of the 

 total. cerebral length, in this specimen it is equal to 50.6 per cent. Ev^en the large 

 callosum of Joseph Leidy, 8.5 cm. in length, is equivalent to 46.7 per cent, of the 

 cerebral length. The cross-section area of the callosum in the brain of Philip Leidy 

 is 7.01 sq. cm., while the average in ten ordinary brains was found to be 5.6.3 sq. em. 

 Other structures, so far as the fragility of the specimen permitted of more or less 

 thorough examination, were of normal and average form and size. 



A. p. S.— XXI. FF. 4, 11, '07. 



