Monstrosities 
duced perfect, as that a complex machine 
should have been invented by a man in a 
perfect state. Under domestication monstrosities 
sometimes occur which resemble normal struc- 
tures in widely different animals. Thus pigs 
have occasionally been born with a sort of 
proboscis, and if any wild species of the same 
genus had naturally possessed a proboscis, it 
might have been argued that this had appeared 
as a monstrosity; but I have as yet failed to 
find, after diligent search, cases of monstrosities 
resembling normal structures in nearly allied 
forms, and these alone bear on the question. If 
monstrous forms of this kind ever do appear in a 
state of nature and are capable of reproduction 
(which is not always the case), as they occur 
rarely and singly, their preservation would de- 
pend on unusually favourable circumstances. 
They would, also, during the first and succeeding 
generations cross with the ordinary form, and 
thus their abnormal character would almost 
inevitably be lost.” But, in a later edition of the 
Origin of Spectes, Darwin seems to contradict 
the above assertion: ‘It should not, however, 
be overlooked that certain rather strongly marked 
variations, which no one would rank as mere 
individual differences, frequently recur owing to 
a similar organisation being similarly acted on— 
of which fact numerous instances could be given 
with our domestic productions. In such cases, 
57 
