24 



BULLETIlSr 797, TJ. S. DEPARTMEISTT OF AGRICULTURE. 



more {iigs. 11 and 13), wliich are removed and grown to flowering 

 size. The degree of splitting varies greatly, even in members of the 

 same genus, and is modified b}^ both cultural and handling methods. 

 In practice, this is the commercial method of increasing the stocks of 

 tulips and narcissi, and to some extent of hyacinths. The repro- 

 duction of the narcissus by this method will mean approximately 

 a doubling each year. In the case of Darwin tulips about an 80 per 

 cent increase each year may be expected, and in single early tulips 

 a little less than this. So many factors are involved that it is very 

 difficult to give exact figures. 



While the propagation of the Roman hyacinth is essentially the 

 same as that of the narcissus, the Dutch hyacinth is reproduced by a 



Fig. 14. — A scooped hyacinth bulb ready to 

 be planted after in incubation period of 

 three months in artificial heat. 



Fig. 15. — A scored hyacinth bulb ready to 

 be planted after an incubation period of 

 three months in artificial heat. 



very artificial process. It consist's essentially of the destruction of 

 the growing point of the bulb, causing the development of many 

 growing ]3oints on the callused edges of the severed scales. Two forms 

 of this artificial reproduction are practiced. One known as the 

 " scooping " method (fig. 14) consists of cutting out a convex section 

 of the bulb base, removing the basal plate entirely and making the cut 

 parallel to its upper surface. This is done with a curved scalpel or 

 a round-bowled spoon sharpened on the edges. The other, known as 

 the "scoring" method (fig. 15), consists of making two to four cuts 

 with a sharp knife across the base of the bulb, each cut being the 

 diameter of the circular base and passing entirely through the basal 

 plate and intersecting the other cuts in the growing point, which is 

 destroyed. 



It is a common practice to dip the cut surface of the scooped bulbs 

 in a little air-slaked lime mixed with dry sand to hasten their drying 



