44 
Split-Hand and Split-Foot Deformities 
It is of first importance, from the point of view which we are considering, that in 
reports of family affections the whole genealogical tree be investigated as accurately 
as circumstances permit. Many of those who have written on deformities of the 
hands and feet have contented themselves with an account of affected members 
only. The tendency of members of the later generations to be acquainted only with 
the deformed relatives preceding them is very great and the fallacies arising from it 
must be carefully guarded against*. It is possible that certain cases in which 
dominance of deformed members is in great excess in the earlier generations may 
be accounted for to some extent in this way. 
Although clinical observation may fail to contribute so richly to the questions 
at issue in dealing with hereditaiy problems, as do observations on the lower 
grades of animal and plant life, and though to a large extent laws formulated from 
the latter must serve as a basis in the discussion of similar problems in man, yet the 
study of hereditary deformities forms a by no means unproductive field of research. 
And the harvest from it remains at present almost totally ungathered. 
The principles governing transmission in man are assuming daily an aspect of 
greater importance, both from the academic and practical standpoint, and there is 
every prospect that their elucidation will be of vital importance in the near future. 
(h) Maternal impressions. In the literature of deformities of the extremities 
a history of maternal fright occurs with great constancy. It appears to be as great 
a matter of indifference, as to in what period of gestation the "impression" was 
produced, as it is of little consequence whether the child's deformity is identical 
with the object which is attributed as its cause. 
In connection with our family, Anderson originally stated that the condition 
was attributed to a packet of lobsters. The legend is now content to impute it to 
a crab. The whole subject would be unworthy of mention were it not for the fact 
that the superstition is not only firmly rooted in the minds of the lower classes, but 
appears to find favour with certain medical writers^' "^'"f. It is to be explained in 
great measure by their want of recognition of common teratological defects and 
monstrosities. We have no intention of dealing further with a theory which has 
been satisfactorily interred by numerous writers, but content ourselves by referring 
to the remarks of Forster, Vrolik and Lewis. 
(c) Origin in an acquired lesion {Extrauterine). The old controversy of the 
Lamarkian doctrine, as opposed to the antagonistic theory of the exclusive 
transmission of " in-born " characteristics, is one which it would be out of place for 
us to enter upon at any length. 
To those -who have never undertaken the task of compihng a genealogical tree of a family 
of working class people the difficulties may not be apparent. Taking the " G " family, it is the rule for 
the adults to be unaware of the names of many of their brothers and sisters and it sometimes happens 
that the names and number of the children are unknown to a parent. 
t The possibility is discussed at some length by some writers, who have mentioned the possibility of 
transmission by recurring "impressions" from the children (compare"). 
