Wyman.] 444 [April 15, 



we must remain content with cranial measurement for the present, 

 and apply the corrections hereafter. 



If we set aside shot as not well adapted to the purpose of measure- 

 ment on account of their weight, a material suitable for equally accu- 

 rate measurement is still a desideratum. Peas are not of a uniform 

 size, though by sifting, uniformity may be approached, and there is a 

 certain amount of error growing out of their want of sphericity, though 

 this is quite small. Spheres of porcelain of the size indicated above, 

 and still better of aluminium, on account of its lightness, would give 

 the required qualities for accurate measurement. 



The results obtained by various observers in making comparative 

 measurements of crania point to one of the following methods as the 

 most desirable. 



I. a. Fill the skull and weiyli the contained material. 



b. Convert weight of material into cubic measurement by determining the 



cubic measurement of a gram or an ounce of material, and multiply- 

 ing this by the whole number of grams or ounces. With proper 

 tables, this would be a quick and easy process, but otherwise a tedious 

 one. 



c. Convert weight of material into brain weight bj- correcting for differ- 



ence in specific gravity. 

 II. n. Fill the skull and measure the contained material. 



b. Convert cubic contents into brain weight by multiplying the number 

 of cubic inches by the weight of a cubic Inch of water (252.5 grains), 

 or the number of cubic centimeters by the weight of a cubic centi- 

 meter of water (one gram), and allowing four per cent, for the differ- 

 ence of the specific gi-avities of brain and water. 



The second has the advantage of being the more simple process, 

 and requires the fewest steps, while the first has the advantage in 

 weighins, which is a somewhat more accurate method than measuring. 

 The v/eight, however, must be converted into cubic measure, if we 

 compare skulls by their cubic contents. With care, either of them 

 are sufficiently correct, and in his choice the observer can and will be 

 guided by his likings. 



2. Position of the Foramen Magnum. 



The flxct, to which attention was called by Daubenton, more than a 

 century ago,* that the foramen magnum is situated farther back in 

 apes than in man, naturally led anatomists to inquire whether any of 

 the human races more nearly approach the a])es in this respect than 

 the rest. Soemmering made the assertion that such is the case 



* Siir la Diflerenco dii Grand Trou Occipital dans I'Homme ct dans los aiitres 

 Animaux, Memoires de I'Acad. des Sciences, ITC-l. 



