THE PHENOMENA OF MUTATION 173 



breeding forms are studied the more difficult it is to 

 understand how they can vary, how a variation can 

 arise. When two forms of Antirrhininn are crossed 

 there is in the second generation such a profusion of 

 different combinations of the factors in the two 

 grandparents, that Lotsy has suggested that all 

 variations may be due to crossing. Bateson does 

 not agree with this. He believes that genetic factors 

 are not permanent and indestructible, but may 

 undergo quantitative disintegration or fractionation, 

 producing subtraction or reduction stages, as in tlie 

 Picotee Sweet Pea, or the Dutch Rabbit. Also 

 variation may take place by loss of factors as in the 

 origin of the white Sweet Pea from the coloured. 

 But regarding a factor as something which, although 

 it may be divided, neither grows nor dwindles, 

 neither develops nor decays, the Mendelian cannot 

 conceive its beginning any more than we can 

 conceive the creation of something out of nothing. 

 Bateson asks us to consider therefore whether all the 

 divers types of life may not have been produced by 

 the gradual unpacking of an original complexity in 

 the primordial, probably unicellular forms, from 

 which existing species and varieties have descended. 

 Such a suggestion in the present writer's opinion is in 

 one sense a truism and in another an absurdity. 

 That the potentiality of all the characters of all the 

 forms that have existed, pterodactyls, dinosaurs, 

 butterflies, birds, etc. etc., including the characters 

 of all the varieties of the human race and of human 

 individuals, must have been present in the primordial 

 ancestral protoplasm, is a truism, for if the possibility 

 of such evolution did not exist, evolution would not 

 have taken place. But that every distinct heredi- 



