Hardesty, Medidla Spi7ialis of the Elephant. i6i 



Table III. Giving the respective dimensions and areas of transverse sec- 

 tions taken from the most enlarged segment of the intumescentia cervicalis of 

 twelve mammals and the relative average size of the largest nerve cell bodies 

 found in the same localities. The diameters are taken within or exclusive of 

 the pia mater spinalis and are from stained sections, the material having been 

 ■dehydrated and embedded in celloidin and probably somewhat shrunken in 

 consequence. The areas were determined by means of the Edixger projection 

 apparatus and the CoKAVti planiineter. The areas of outline tracings of projec- 

 tions of the sections enlarged lo diameters were taken with the planimeler in 

 terms of square millimeters. The results were then reduced by lOO to obtain 

 the actual areas as given in the Table. The areas recorded in column 6 were 

 taken in a similar way, but from separate outline tracings of the gray figure. 

 In column 7 are given for each specimen the area of that portion of the gray 

 figure the dorsal boundary of which runs parallel to and along the dorsal border 

 of the commissura grisea. In this way that part of the substantia grisea which 

 contains the larger cell bodies, is marked off. The differences therefore, between 

 the areas in columns and 7 represent the areas of the columnae posteriores. The 

 average mean diameters of the cell-bodies (col. i) were determined by measure- 

 ment of the ten largest cells in three sections including and adjacent to that sec- 

 tion whose dimensions and area are given. The two dimensions of each cell-body 

 were measured, in each case, under a magnification of 712 diameters (Zeiss). 

 The valua of the spaces of the ocular micrometer were determined by means of 

 a stage micrometer ruled into i-ioo mm. The method followed in judging a 

 •diameter involving the larger dendrites is shown in Plate XIII, where the lines 

 crossing the cell body are the exact lines measured. 



In the first place it is seen from Table III that while the 

 dimensions of the medulla spinalis decrease gradually down the 

 series, they are by no means constantly proportional to the size 

 of the animal, nor do they vary with the variations in body 

 weight. The adult elephant having a body weight of 8,000 

 pounds^ is about six times as large as the average horse, ^ while 



1 The elephant from which the present specimen was obtained was estimated 

 to weigh about 8, 000 pounds. From measurements recorded by ScLATER ('79) 

 and from information obtained through the kindness of the Zoological Society 

 of Philadelphia, it appears that 8, 000 [pounds is a fair average for the Indian 

 elephant. "Jumbo" reported to have been the largest elephant in captivity was 

 not the heaviest. His great height (over 12 ft.) consisted in disproportionately 

 Jong legs and a hump in his back. "Bolivar," the large Indian elephant now 

 in the Philadelphia Zoo is probably actually the heaviest ever in captivity in 

 America. His weight is now estimated at 12,000 pounds and he is 10 feet high. 

 The African elephant is more slender than the Indian or Asiatic and probably 

 does not weigh as much in the average. "Jumbo" was an African elephant. 

 In a paper published in 1722, Stukeley mentions having read of an elephant 

 which had a height of 14 feet. He also notes that the African elephant is less 

 in size than the Indian and is of a darker color, 



^ The horse dealers consulted place the average weight of the ordinary 

 horse at 1,-250 pounds. Rarely does even the draft horse acquire 1,800 pounds. 



