xii IMPEOVING CULTIVATED PLANTS 147 



schemed, and quarrelled, and robbed, to get posses- 

 sion of precious kinds ; bow the bulbs had to be 

 watched night and day to prevent the offsets being 

 stolen. These and a great many other curious 

 stories we might tell, but at present it is sufficient 

 for us to know that these wonderful tulips were 

 produced by crossing. The fact was, however, kept 

 a profound secret, and it was not till nearly a 

 century afterwards that crossing came into general 

 use as a means of improving cultivated plants. 

 The " tulip mania," as it was called, was as foolish 

 as most manias, but it did one very important 

 thing it taught gardeners in general how they 

 might improve their plants ; how they might 

 apply the knowledge that the botanists had been 

 slowly and carefully collecting. 



In the next chapter we shall have to consider 

 exactly what crossing means, and how it is carried 

 out. In concluding this chapter let us just notice 

 what selection and crossing have done in the case 

 of one cultivated plant, the wheat plant. 



Wheat, as we have already seen, was originally 

 a cultivated plant of the Mediterranean zone, where 

 the winters are mild and wet, and the summers 

 hot and dry. The plant there was always sown in 

 autumn, grew through the warmth and wet of 

 winter, and ripened in the bright sunshine of 

 summer. But it will not stand a very severe 



