81 
numerous duplicates in the collection to confuse me I continued 
arranging the photographs until the stages became thoroughly fixed, 
that is, until a misplaced photograph could be replaced with its stage 
with ease and until all the duplicates fell together. At first some of 
these duplicates fell two stages apart, showing that all the stages 
made at first were not reliable. Finally when the arrangement was 
made as satisfactory as possible I found that fourteen stages remained, 
six having been eliminated. This arrangement is given in the ac- 
companying table. In making the table the photographs from illus- 
trations in the literature, photographs of embryos in other collections, 
and those from my own collection are blended. Also when there are 
photographs of both sides of an embryo they are counted as one. 
TABLE 
266 human embryos from two to twenty-five millimeters long arranged 
in fourteen stages showing variations in length and the number of specimen 
for each stage. 

K/L/M[N|O/P/Q/R|si|T|Ul. 
te 
Stages ET 


2mm.| 3 | 

Do — bb 
7 | bite | 

| 

Qo 
bt ke CO DT C w 
or 
m 

er 
S 
eer 
et Co Cc G DO 

Pm OHH Owe 
= 



_ 
or 
eS OHO Ee CO 
onnory I 



DO 
oO 
e 
— 
oo 
NrE NOK OD We DH 
DH & Ow Re 
2 | | 
| 



25 | 1 
Total| 3 | 7 [12 [10 
_ 
| 2 
7 |a2 |21 23 |30 | 9 |36 |21 |20 | 5 | = 266 
Anat. Anz. Bd. 46. Aufsätze. 6 




bo 
