of nervous
disease are inherited, the most superficial consideration shows. A
child in its mental characteristics is said to take after one or the
other of its parents, certain habits and mental traits are the same,
often even the handwriting of a child resembles that of a parent.

In certain cases the inheritance is transmitted by the female alone.
This is the case in the haemophilia, the unfortunate subjects of which
are known as bleeders. There is in this a marked tendency to
haemorrhage which depends upon an alteration in the character of the
blood which prevents clotting. This, the natural means of stopping
bleeding from small wounds, being in abeyance, fatal haemorrhage may
result from pulling a tooth or from an insignificant wound. There is a
seeming injustice in the inheritance, for the females do not suffer
from the disease although they transmit it, while the males who have
the disease cannot even create additional sympathy by transmitting it.

The most obvious inheritance is seen in the case of malformations.
These represent wide departures from the type of the species as
represented in the form. There is no hard and fast line separating the
slight departures from the normal type known as variations and
mutations, from the malformations. Certain of the malformations known
as monstrosities hardly represent the human type. These are the cases
in which the foetus is represented in a formless mass of tissue, or
there is absence of development of important parts such as the nervous
system or there is more or less extensive duplication of the body.
There has always been a great deal of popular interest attached to the
malformations owing to the part which maternal impressions are
supposed to play in their production. In this, some striking
impression made on the pregnant woman is supposed to affect in a
definite way the structure of the child. The cases, for instance, in
which a woman sees an accident involving a wound or a loss of an arm
and the child at birth shows a malformation involving the same part.
There is no association between maternal impressions and
malformations, although there have been many striking coincidences.
All malformations arise during the first six weeks of pregnancy known
as the embryonic period, in which the development of the form of the
child is taking place, and during which time there is little
consciousness of pregnancy. Maternal impressions are usually received
at a later period,