20 (212) SURPASSING UPWARD AND DOWNWARD OF THE INDICES 
sisters (1920b, table B3) have all brachycephalic indices (80.5—84.5). 
Some have children with high and very high indices. Here we see a 
working of selection. According to the polymery-theory we must here 
accept mendelizing of many polymere factors in a homozygote form. 
However we find too many children with a very high index here (see 
also p. 41). 
In table III of family 322a the four grand-parents are dolichoceph- 
alie. More or less all six children surpass the indices of parents. Here is 
some selection-working in the minus-direction. 
Family 182. The paternal grand-fathers are both dolichocephalic 
(79.8). Of the maternal grand-parents the grand-father is dolicho- 
cephalic, the grand-mother is verymuch brachy cephalic (1920b, 182c),a 
2nd brother is dolichocephalic. In this case there might be some pre- 
potence of the father which might be based upon ancestral influence. 
In family 34a there is on a large scale a surpassing of the parents’ 
indices by the children’s. As for the parents there is here an evident 
prepotence for the low indices and for the children a working of 
selection. 
- Family 269c. Here we might speak of dominance of the father’s 
index. Both paternal grand-gathers are dolichocephalic. The grand- 
mother has a very low index (79.5) which is still somewhat lower than 
the lowest of the grand-children. In analogy of other cases we may 
speak here of prepotence of the index of the father through ancestral 
influence. We may also suppose that the hereditary factor (or factors) 
for the low index of the grand-mother has passed on the father and 
has been segregated in one or two of the grand-children. 
Family 34e shows dominance and prepotence of the low index. 
Here the grand-fathers are not known (1920 table A 34e). 
~ The results of the tables I—III may be resumed as follows: 
1. There is a large non-hereditary variability (1920 c, p. 24). 
2. There is segregation. 
3. There is dominance of the high index over the low one with a 
large variability of the heterozygotes. 
4. There are different hereditary variations of the head-index. 
5. Thesame exteriour (phaenotypical) variations can have a different 
hereditary constitution. 
6. Small and short heads have often high indices. 
: 7, The presence of multiple heredity-factors for the head-index is 
aid 
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