336 POPULAR SCIENCE MONTHLY. 



principle that only combinations, but no primary characteristics, were 

 produced. Only in one instance I encountered what seemed to be an 

 absolute exception to this rule. It was an announcement of Lemoine 

 of Kanej', the most celebrated breeder of garden novelties in France. 

 He claimed that he had been able to produce by crossing double 

 lilacs. Double flowers remain longer on the branches than the single, 

 which usually drop off after a few days. To find out how it was pos- 

 sible to develop by crossing from single lilacs new varieties with entirely 

 new characteristics I visited Lemoine in Xancy. Walking through his 

 gardens. I put the question to him and received the following answer: 

 " That is very simple. As a boy I had seen in the garden of an old 

 relative a specimen of Syringa azurca, a very rare lilac of an ancient 

 type with double flowers. Remembering this, I bought that tree from 

 the person who owned my relative's home. With this tree I crossed all 

 varieties of single lilacs I had and got the double variety." Here we 

 find again the same procedure : first buying, then crossing, later graft- 

 ing or budding on other forms, but no creation of an absolutely new 

 character. The number of combinations may be unlimited, yet the 

 creation of new prime characters is entirely excluded. 



This principle came into full evidence while we were in Burbank's 

 grounds. He demonstrated to us ' white blackberries ' with large fruit 

 of a delicious flavor, which now are an article of commerce. I asked 

 him about the origin of this crossing. Burbank explained that here 

 and there in California occurred a wild blackberry with white fruit. 

 He had crossed this plant with other forms. A white variety of the 

 common raspberry has similarly been known in Eurpoe since olden 

 times. 



Another striking example is furnished by the spineless cactus, one 

 of the novelties of which Burbank expects much. It is one of the 

 Opuntias, a desert plant, the fruit of which is eaten and known as 

 Indian figs. Its stem consists of big, flat slabs, joined together in the 

 most fantastic manner. It reaches a height of six feet, spreading 

 widely and growing luxuriantly. The fruit is much relished by cattle, 

 as it is juicy, rich in foodstuff and has but few thorns. The wbole 

 plant is eaten by animals only when they are driven to do so by hunger, 

 as it is covered with hard prickly thorns. If the plant is cooked for 

 some time the thorns soften and the cactus becomes a nutritious food. 

 This process of cooking is, however, too expensive for practical pur- 

 poses, and hence a cactus without thorns would transform a barren 

 desert into rich pastures. To reach this Burbank brought together 

 villi Opuntias from Mexico, South Africa and various other countries 

 as well as the commonly cultivated species. Among the specimens 

 Burbank received, one was accidentally found without prickles on the 

 Leaves and another with no thorns on the vonno- shoots. It was, there- 



