M 



PROPAGATION' OF PLANTS. 



dergoing a change of structure. A cell near the base 

 of the detached scale draws to itself the cell-matter of 

 an adjoining one, the two add other cells, all deriving 

 their support from the contents of the old cells, and 

 from these reservoirs of nutriment a new scaly bulb of 

 the exact type of the old or parent bulb is built up, just 

 as occurred in the formation of a new tuber out of the 

 materials of the old one in the Potato. Sometimes sev- 

 eral bulbs will be produced from a 

 single scale, as the formative principle 

 may become active in one or more cells 

 at the same time. These scales, in 

 their aggregate form, make a complete 

 or perfect bulb, are really sessile sub- 

 terranean leaves, which, as shown, 

 possess an inherent power of repro- 

 ducing their kind in the absence of 

 any additional organic material fi;om 

 other sources. 



That the cell-matter of these sub- 

 terranean scales or leaves is not specifi- 

 cally different from that of which the 

 upper or stem leaves is composed, is 

 readily shown when the old or main 

 bulbs are planted so deep that a few 

 inches of the base of the flower stem 

 will be covered with soil. The flower 

 stems of this species of Lily, as stated, 

 produce leaves along their entire length, 

 but those below the surface of the 

 ground are prevented from developing 

 into true aerial leaves ; consequently 

 the cell-matter provided by other parts of the plant is re- 

 organized and becomes small bulbs (figure 6), which emit 

 roots for their individual use and support later in the 

 season, when they will be cast off by the mature and 



Fig. 6. 



TiTT.T BULBS ON THE 

 FLOWEE STEM. 



