424 Studies in the Theory of Descent. 



From this comparison we perceive that the 

 process of transformation has at least become pre- 

 liminarily concluded in the Genoese form. Why 

 the backward transference of the newly-acquired 

 character to the young stages has not yet occurred, 

 or, at least, why it is not in progress, does not 

 appear ; neither can it be stated whether this will 

 take place later, although we may venture to sup- 

 pose that such will be the case. At first sight but 

 a relatively short time appears necessary for the 

 single stage V., which is still in a state of fluctua- 

 tion (variable), to become constant by continued 

 crossing, like all the other stages. 



That the transformation is still in full progress 

 in the German form, is shown by the fact that in 

 this case all the stages are variable with the ex- 

 ception of the first the second stage being only 

 variable to a small extent, the third to a much 

 greater extent, and the fourth to the highest 

 degree conceivable, whilst the fifth and last stage 

 is again less variable so that the greatest struggle 

 between the old and new characters takes place in 

 the fourth stage. 



Among the innumerable variations presented by 

 this last stage a complete series of transitional 

 forms can be arranged so as to show the gradual 

 conquest of the black by the green, and thus 

 indicating, step by step, the course which the 

 latter colour has taken. 



In the blackest specimens there is nothing 



