VARIATION UNDER NATURE 76 



modification directly due to the physical conditions of 

 life; and "variations" in this sense are supposed not to 

 be inherited; but who can say that the dwarfed condition 

 of shells in the brackish waters of the Baltic, or dwarfed 

 plants on Alpine summits, or the thicker fur of an ani- 

 mal from far northward, would not in some cases be 

 inherited for at least a few generations? and in this case 

 I presume that the form would be called a variety. 



It may be doubted whether sudden and considerable 

 deviations of structure such as we occasionally see in our 

 domestic productions, more especially with plants, are 

 ever permanently propagated in a state of nature. Al- 

 most every part of every organic being is so beautifully 

 related to its complex conditions of life that it seems as 

 improbable that any part should have been suddenly pro- 

 duced perfect, as that a complex machine should have 

 been invented by man in a perfect state. Under domes- 

 tication monstrosities sometimes "^ occur which resemble 

 normal structures in widely different animals. Thus 

 pigs have occasionally been born with a sort of pro- -- din-^ 

 boscis, and if any wild species of the same genus had 

 naturally possessed a proboscis, it might have been ar- 

 gued 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 J 

 mo nstrous forms o f thisjrind ever do appear in a state/ 

 of nature and are capable of reproduction (which is not ) 

 aTways^the case), as they occur rarely and singly, their \ 

 preservation" would depend on unusually favorable cir- 1 

 cumstances. They would, also, during the first and sue- j 

 ceeding^ generations cross with the ordinary form, an(^/ 



