384 Evolution by Jumps 



affecting all organs, and in every degree of magnitude — 

 some so small as to be indistinguishable from the normal 

 individual fluctuation. 



Range and Frequencies of Mutations 



Mutations have been reported for every system of 

 organs in hundreds of species of plants and animals. Nat- 

 urally more is known about organisms in the laboratory, in 



Fig. ^j. Fusion of Bones in a 

 Pig's Foot 



Parts that are ordinarily separate in the 

 members of a species are sometimes fused to- 

 gether, as in a pig with an uncloven hoof. 

 After Bateson. 



the garden and in the breeding pen than is known about 

 wild animals. The indications are, however, that the same 

 kinds of mutations appear in a wild state, but fail of notice 

 because our attention is not directed to them. 



Recessive characters appear as mutations as well as 

 dominant ones; and mutations may show themselves in the 

 loss of some bodily character, or in the fusion of parts, as well 

 as in additions or in gains (Fig. 97) . Some well known 



