492 Mutations 



of a later period. A long list could easily be 

 made, to show that during the whole history of 

 horticulture double varieties have arisen 

 from time to time. As far as we can judge, 

 such appearances have been isolated and sud- 

 den. Sometimes they sprang into existence in 

 the full display of their beauty, but most com- 

 monly they showed themselves for the first time, 

 exhibiting only spare supernumerary petals. 

 Whenever such sports were worked up, a few 

 years sufficed to reach the entire development 

 of the new varietal attribute. 



From this superficial survey of historical 

 facts, the inference is forced upon us that the 

 chance of producing a new double variety is 

 good enough to justify the attempt. It has fre- 

 quently succeeded for practical purposes, why 

 should it not succeed as well for purely scien- 

 tific investigation? At all events the type rec- 

 ommends itself to the student of nature, both 

 on account of its frequency, and of the apparent 

 insignificance of the first step, combined with 

 the possibility of rapidly working up from this 

 small beginning of one superfluous petal to- 

 wards the highest degree of duplication. 



Compared with the tedious experimental pro- 

 duction of the peloric toad-flax, the attempt to 

 produce a double flower has a distinct attrac- 

 tion. The peloric toad-flax is nothing new ; the 



