28 HEREDITY 



new does make its appearance. The sudden appearance 

 of a novelty is what Darwin called a " single variation," 

 and what is, in modern phraseology, called a mutation. 

 It will be well to give one or two historical instances of 

 mutations. 



In this connection we cannot do better than quote 

 Huxley's account of the appearance of the Ancon or 

 otter breed of sheep. He says : "It appears that one 

 Seth Wright, the proprietor of a farm on the banks of 

 the Charles River in Massachusetts, possessed a flock of 

 fifteen ewes and a ram of the ordinary kind. In the 

 year 1791, one of the ewes presented her owner with a 

 male lamb, differing, for no assignable reason, from its 

 parents by a proportionally short body and short, 

 bandy legs, whence it was unable to emulate its relatives 

 in those sportive leaps over the neighbour's fences in 

 which they were in the habit of indulging, much to the 

 good farmer's vexation. . . . The variety appears to 

 have arisen in full force, and, as it were, 'per saltum ; a 

 wide and definite difference appearing at once between 

 the Ancon ram and the ordinary sheep. It is not 

 possible to point out any obvious reason for the appear- 

 ance of the variety to use a conveniently erroneous 

 phrase, the variation arose spontaneously." The Ancon 

 ram was retained and used for breeding, and it is interest- 

 ing to note that its offspring were " either pure Ancons 

 or pure ordinary sheep." The bandy-legged variety of 

 sheep did not prove valuable, and has long ago become 

 extinct, but the history of its origin is interesting. 



The oldest recorded mutation occurred in the rather 

 common garden plant, the greater celandine. In 1590, 

 an apothecary in Heidelberg had some plants of 

 celandine growing in his garden, when there appeared 

 amongst the ordinary specimens a peculiar new form, 

 which had its leaves divided into very narrow lobes, 

 and its petals also cut or lacinated. The cut-leaved 

 celandine breeds true from seed and is now widely 

 grown as a garden flower, but all the specimens are 

 descended from the one original plant which arose 

 unexpectedly as a " sport." 



