162 Retrograde Varieties 



bers during five succeeding generations, but was 

 never able to find even the slightest indication 

 of a reversion to the red prototype. The scar- 

 let pimpernel or Anagallis arvensis has a blue 

 variety which is absolutely constant. Even in 

 Britton and Brown's Flora, which rarely enum- 

 erates varieties, it is mentioned as being prob- 

 ably a distinct species. Eight hundred bloom- 

 ing seedlings were obtained from isolated 

 parents, all of the same blue color. The New 

 Zealand spinage (Tetragonia expansa) has a 

 greenish and a brownish variety, the red color 

 extending over the whole foliage, including the 

 stems and the branches. I have tried both of 

 them during several years, and they never 

 sported into each other. More than 5000 seed- 

 lings, from the different seeds of the same 

 fruits, were grown in the succeeding years, but 

 neither those germinating in the first year, nor 

 the others coming into activity after four years 

 of repose, gave any sign of the red color of the 

 original species. 



It is an old custom to designate intermediate 

 forms as hybrids, especially when both the 

 types are widely known and the intermediates 

 rare. Many persons believe that in doing so, 

 they are giving an explanation of the rarer 

 forms. But since the laws of hybridism are 

 coming to be known we shall have to break with 



