MEMO1HS OF T1IE NATIONAL ACADEMY OF SCIENCES. 181 



character which the angle of Daubenton expresses is not of "a serial anthropological character,"* 

 or to think that the pressure on the occiput, before referred to ( 7), has influenced the position of 

 the foramen magnum. It is not, however, in the most flattened skulls that we find the highest 



angles. 



$ 13. CAPACITY OF CRANIAL CAVITY. 



We have already stated that it was found necessary to repair the greater part of the skulls of 

 this series with plaster of Paris. This often so encroached on the cranial cavity as to make it 

 impossible to determine the cubic capacity of the latter. In 8 skulls only were we able to find 

 the cubic contents of the brain case, and these were so friable that neither water nor shot 

 could be used in them. The measurements were made by means of mustard seed; not according 

 to any method previously laid down for the use of this seed, but by a system of our own, approxi- 

 mating closely to Broca's method for the use of shot. 



The plan is as follows : Use the funnels, rammer, and tin vessels as for shot cubature. Use 

 the 2,000-centimeter graduated glass with its leveling rammer. First, lay the skull on its vertex. 

 Pour in rapidly a liter of seed through the wide-necked funnel. Pour in, in same way, so much 

 more seed that when the skull is set upon its face and frontal bone the seed will form nearly a 

 level across the skull from foramen to near middle of sagittal suture. Second, insert large end of 

 rammer into foramen, gently press seed toward frontal region, with side of rammer in such a way 

 as to level the surface of whatever quantity of seed is in the skull. Third, fill small-necked fun- 

 nel with seed; hold it in left hand with finger over its mouth. The skull, as has been said, is 

 standing on its frontal region. Grasp occiput with right hand and slowly incline the skull into 

 the vertex-downward position as before, while running in seed through small funnel. During this 

 operation the seed will overflow the foramen three or four times; when it does so, thrust seed into 

 skull with forefinger of right hand ; but as soon as pressure is felt, stop pressing. When the finger 

 can no longer be introduced into the foramen without feeling decided resistance, and the skull has 

 been completely lowered into vertex-down position, let the seed form a heap over foramen, press 

 this heap vigorously into foramen with right thumb, and add seed to level foramen. Fourth, 

 cover foramen with cotton wad and shake stray seeds from surface of skull. Fifth, empty con- 

 tents of skull into double liter tin. Pour all the seed as rapidly as may be from double liter into 

 2,000 c. c. eprouvette, using no funnel. Bring leveling rammer of eprouvette down firmly, but not 

 violently, on seed to level it. Sixth, read the eprouvette. 



That the above method gives good results which fairly admit of comparison with results 

 obtained by shot, there is little doubt, for the following reasons: We made according to this plan 

 five measurements on one of Professor Ranke's bronze skulls, which was presented by the inventor 

 to our Museum. The capacity of this bronze cast, as ascertained by ourselves, with water, atmos- 

 phere, and all accessories at a temperature of 60 F., was 1,240 c. c. (The bronze is marked 1,250 

 c. c., butthis seems to be an error.) Our measurements of the capacity of this object with mustard 

 seed ranged from 1,230 -f to 1,250, with an average of 1,242. We made measurements on this 

 plan of some natural skulls in our collection which had been repeatedly measured with water and 

 with shot according to Broca's system, and, applying three or more measurements to each skull, 

 we arrived at results more uniform than those obtained with the artificial skull of Eanke. The 

 mustard seed gave as a rule higher figures than those obtained by shot or water, but the average 

 excess was less than 1 per cent. 



Of the eight skulls measured four were male, two female, and two of doubtful sex. With 

 such a small series we have not considered it proper to study the capacity of the sexes separately. 

 The highest capacity belongs to a female skull, the lowest capacity to a skull of unknown sex. 

 All the specimens pertain to subjects of mature age, and none are senile. 



The highest two capacities are, in cubic centimeters, 1,530 and 1,510, which according to 

 Broca's nomenclature t belong to skulls of the medium or ordinary class. Four capacities, viz, 

 1,390, 1,330, 1,310 and 1,170, belong to his class of small (petite) skulls. The remaining two 

 capacities, 1,150 and 1,120, belong to the niicrocephali or lowest class. The average capacity is 

 only 1,313. It might be urged that since our series of capacities represent such a small proportion 



' Op. tit., p. 814. tTopiNARD, op. cit., p. 610. 



