Multiplication of Extremes 761 



multiplication, previous to being given to the 

 trade. I wondered, and asked, why no pure 

 white variety was present. His answer was: 

 ^^ Because no white species had been found up 

 to the present time, and there is no other means 

 of producing white varieties than by crossing 

 the existing forms with a new white type. ' ' 



Comparing the varieties produced in succes- 

 sive periods, it is very easy to appreciate their 

 gradual improvement. On most points this is 

 not readily put into words, but the size of the 

 petals can be measured, and the figures may 

 convey at least some idea of the real state of 

 things. Leaving aside the types with small 

 flowers and cultivated exclusively for their 

 foliage, the oldest flowers of Canna had 

 petals of 45 mm. length and 13 mm. breadth. 

 The ordinary types at the time of my visit had 

 reached 61 by 21 mm., and the '' Madame 

 Crozy ' ' showed ^^ by 30 mm. It had however, 

 already been surpassed by a few commercial va- 

 rieties, which had the same length but a breadth 

 of 35 mm. And the latest production, which 

 required some years of propagation before be- 

 ing put on the market, measured 83 by 43 mm. 

 Thus in the lapse of some thirty years the length 

 had been doubled and the breadth tripled, giv- 

 ing flowers with broad corollas and with petals 



