Page:Natural History Review (1861).djvu/221

Rh {| align="center" cellpadding="3" cellspacing="0"
 * rowspan="3" | c : d
 * rowspan="3" |
 * In Orang = 1 inch. : 3 inch. = 1 : 2⋅40.
 * In Man = 1 inch. : 4 inch. = 1 : 2.75
 * In Chimpanzee = 15⋅5′′′ : 32⋅5′′′ = 0⋅48 : 1.
 * }
 * In Chimpanzee = 15⋅5′′′ : 32⋅5′′′ = 0⋅48 : 1.
 * }

The following six measurements of height, breadth, and length of the human cerebral hemispheres, are the three maximum and the three minimum measurements given by Husche, at the ninety-ninth page of his work, already referred to.

From these measurements, it is evident that the variations of height oscillate within narrower limits in the human brain than the variations either of length or of breadth. The measurement of height, therefore, would seem to possess greater serial importance than either of the other two measurements. Yet the following measurements will show that it is precisely in this dimension that the brain of the apes stands in the greatest relative inferiority to that of man.

Length of hemispheres in Orang : length in Man = 4 in. : 6–7 in. = 1 : 1⋅4 or 1 : 1⋅64. „Chimpanzee :„= 99 in. : 6–7 in. = 1 : 1⋅54 or 1 : 1⋅79.

Breadth of ditto in Orang : breadth in Man= 3 in. : 4–7 in. = 1 : 1⋅23 or 1 : 2⋅15. „Chimpanzee :„= 95 m. : 4–7 m. = 1 : 1⋅08 or 1 : 1⋅88. „„„= 87 m. : 4–7 m. = 1 : 1⋅17 or 1 : 2⋅06.

Height of ditto in Orang : height in Man= 2 in. : 5 = 1 : 2⋅35. „Chimpanzee :„= 54m. : 5 = 1 : 2⋅38. „„„= 64m. :5 = 1⋅2.

Of all the differences of measurements and their relations as yet adduced, the difference between the relative heights of the human and the simious brains seems the most important.

Small as the difference in the two measurements of corpora callosa may seem, we must yet record that posteriorly to the posterior bourrelet or rounded edge of that body in the orang, the corpora quadrigemina came into view when the brain was removed from the skull. This observation will be seen later to have, when coupled with certain others, considerable value, as showing the greater relative shortness of the corpus callosum. It was noticeable that the anterior pair of corpora quadrigemina were less sharply marked off from the posterior than in man.

The central notch of the cerebellum was much shallower relatively