453 
reconstructed by Born’s wax plate method. The first, which is re- 
presented by Figs. 2 and 3, is a finished model carefully reconstructed 
by Mr. Bonnot to show the form and relations of the cervical, thoracic, 
abdominal and pelvic viscera, together with the large blood vessels. 
The second was a rough model reconstructed by Dr. SEEVERS in order 
to determine the volume of a) the entire embryo and b) the principal 
parts and organs of the embryo. The volumes were measured by the 
water-displacement method, and then the actual volume was computed 
by dividing the result by the cube of the enlargement (75 diameters). 
The work was done under the direction of Prof. C. M. Jackson, 
to whom we are indebted for assistance in various ways. 
The following table shows the volume of the model and also the 
(computed) actual volume of the embryo and the various parts. 
Table I. 
Volume of Embryo No. H60 (11 mm). 
Volume of Actual 
Parts of Body Model Volume 
Entire embryo 41 200 ce. OOS Ors ee: 
Head of embryo 18300 ,, 0,0434 „ 
Trunk (without limbs) 20700 ,, 0,0491 ,„ 
Upper extremities 20055; 0,0028__s,, 
Lower extremities 10005; O0023 
Brain 8330, 0,0198 ,„ 
Spinal cord 2000 ,, 0,0047 „ 
Lungs HU, 0,00035_,, 
Heart 150075; OO0S5s 7 
Liver 2.0007, 0,0047 -,, 
In the next table, the absolute volume and the percentage of the 
total volume of the body is given for the various parts of the embryo. 
Table II. 
Volumes of Embryo, Newborn, and Adult. 
11 mm. Embryo Newborn Adult 
volume apy a volume | °/, of volume | °/, of 
es whole Gc: whole cc. | whole 
Whole body 0.0976. 121009 &.\, S440" 1-100 60000 | 100 
2 TE 
Heart | 0,0035 | 3,64 | 20 |) 0,58 | 300 0,5 
| | 25 96 
Lungs | 0,00035 | os6 | | YS 1542 2,57 
Liver 0007 | 4.85 | | nae { 372 | 1468 2,44 
Brain | 0,0198. | 2026 | 3717| 108 | 1314 2,19 
Spinal cord 0,0047 | 485 | 3,9 0,11 25,1 0,04 
Head 0,0434 | 44,42 
Trunk 0,0491 50,12 | 
Upper extremities 0,0028 2,91 | 
Lower extremities 0,0023 | 2,43 | 
