184 The Origin of Species by Mutation. 



Many forms which are put on the market as new are, 

 from our point of view, really quite old. I mention as an 

 example the famous double Lilacs which Victor Lemoine 

 of Nancy put on the market in the '80's. They consist of 

 a number of new^ and in many respects excellent varieties 

 which have now found a place in many gardens and parks. 

 Thev were offered as new ; and I was anxious to find out 

 how the ^'doubling" had been attained. I went, therefore, 

 in 1892 to Nancy and asked M. Lemoine. After he had 

 shown me his plantations of Lilac he told me the follow- 

 ing story of their origin. "In 1870 I happened to see in 

 a garden in Luxembourg, a double specimen of Syringa 

 vulgaris azure a plena, a little-known form which is seldom 

 seen in gardens. When some years later I came to think 

 of growing Lilacs I simply bought this plant and crossed 

 it with almost every variety on the market." This was 

 the way in which he got his novelties. But as to the 

 origin of doubling he was completely in the dark. Later 

 I found that Hunting had mentioned the double form 

 as early as 1671. 



We know just as little about the origin of the Cactus- 

 dahlias which threaten to supersede all other kinds owing 

 to their great variety, and to the splendor of their flow- 

 ers. They are the result of a cross between one single 

 plant and numerous older varieties. When I visited Mr. 

 Van den Berg in Jutphaas who introduced this novelty, 

 he gave the following account : "Many years back (1872) 

 I asked a correspondent of mine in Mexico to send me 

 a case of bulbs, roots or rhizomes of any kind of foreign 

 plants he could possibly get hold of. The contents of 

 the box reached Holland in very bad condition : almost 

 everything was rotten; in fact everything but a single 

 tuber which however produced a shoot. This plant was 



