CONSANGUINEOUS MARRIAGES 247 
garded as the inevitable consequence of Mendel’s law of inheri- 
tance. Where a defect is inherited by two parents from a common 
ancestor their union is naturally followed by the production of 
the defect in question. It may be seriously doubted if inbreeding 
does more than this or is ever strictly speaking the cause of defect 
of any kind; it simply makes manifest defects that are already in 
the germ plasm. 
It must not be forgotten that if inbreeding sometimes brings 
out undesirable qualities it may also conserve good ones. A 
conspicuous example of a consanguineous marriage which was 
productive of most fortunate results is afforded by the marriage 
of Charles Darwin with his first cousin, Emma Wedgewood. The 
Wedgewoods, like the Darwins, belonged to a noteworthy family. 
Josiah Wedgewood the founder of the works that make the well- 
known Wedgewood pottery was a F. R. S. as was also the cele- 
brated Erasmus Darwin. All of Darwin’s sons became celebrated 
for their intellectual achievements and are noteworthy for being 
unusually able and normal types of men. 
A good deal of close intermarrying has occurred in the Walcotts, 
Edwards, and other old New England families who have produced 
many of our most able men. Consanguineous marriages have 
probably been a means of conserving superior ability in some of 
the royal families of Europe, although in others they have served 
to bring out a neuropathic inheritance. 
The effect of crosses between different races and peoples has 
been the subject of no end of discussion. Naturalists, historians, 
anthropologists, travelers, missionaries, and casual observers of 
all descriptions have contributed to swell the volume of literature 
which has been accumulating on this subject since the days of the 
author of Leviticus. Even the most competent observers have 
come to opposed conclusions, and it is not rare to find the same 
mongrel race spoken of by different writers in quite contradictory 
terms. No one can read much of the literature on race crossing 
1 That cousin marriages in England are no more harmful than ordinary mar- 
riages is indicated by the statistical investigations of George Darwin (Jour. Roy. 
Stat. Soc. 38, 153-182, 1875.) 
