30 (222) SERIES OF INDICES OF WHICH A SINGLE 
Family 196. We do not know any other members of this family. 
Here the son with the brachycephalic index has a much smaller head. 
than both other children. In connection with the former families we 
may here presume that one of the parents or both parents have the 
hereditary constitution DR. This is also available for family 27, where 
we should prefer the formula DR x DR = DD + 2DR + RR, as of 
six children but one is brachycephalic (For therest see also theremark 
on pe SL). ; 
For family 298 we accept the formula DR x RR; the dolichoceph- 
alic index of the mother is here reversed dominant (p. 34). For family 
224 we may accept the formula DR x DR, unless the brachycephalic 
son be a non-hereditary pathological modification (p. 26). Then in 
family 224 we should have to see a hereditary dolichocephalic family. 
In family 164 the brachycephaly of the youngest daughter is probably 
a pathological modification (p. 27). The family is then hereditary 
dolichocephalic. 
For family 228a it is obvious that we have to accept segregation 
according to the formula DR x DR = DD + 2DR + RR or DR x 
RR = DR + RR. 
Family 19a. The index of the father contains (see p. 27) micro- 
brachycephaly through the grand-mother. So we may here accept the 
formula DR x RR. Wether we have to consider the sons with the 
indices 80.5 as DR is doubtful; in the dolichocephalic family 19 were 
also 2 children with the index 80.5. 
In my opinion the results of table V lead to the view that in many 
of these families is segregation. The explanation of the presence of a 
single low (dolichocephalic) index did not raise difficulties, as we had 
already learned to keep account with a more or less evident dominance 
of the high index. 
If there is a single high (brachycephalic) index in a series of low ones, 
we may accept reversed dominance. Here it is important that this 
reversed dominance very often occurs in families where the parents 
have small heads and that especially the deviating brachycephalic 
index among the children belongs to a small head. We herefrom deduce 
that in small heads there is some dominance of dolichocephaly over 
brachycephaly. This recessive brachycephalic index: is however not 
such an independent property that f. i. it segregates from parents with 
very large heads. An indication of the occurence of a brachycephalic 

