SECT. III. GEMS. 409 



This definition is obviously applicable, in one The bulb, 

 alternative or other, both to the bud and bulb ; by 

 which last it is well known that the species is often 

 propagated, as in the very common case of bulbous 

 rooted plants. If the bulb of a Snow-drop or Lily 

 is taken up when the season of flowering is past and 

 deprived of its external coats or scales, the rudiments 

 of young bulbs will be discovered lurking at the 

 base of the scales in the form of small buds, though 

 some may perhaps be found farther advanced and 

 ready to burst their integuments ; which after they 

 have ultimately done, they then detach themselves 

 from the parent bulb altogether and form new indi- 

 viduals. Such is the mode of the propagation of the 

 radical bulb. 



But the species is also often propagated by means 

 of the caulinary bulb. This bulb generally appears 

 in the axil of the leaves, as in Dentaria bulbifera 

 (PL III. Vol. I.), and Lilium bulbiferum. At first 

 it seems a sort of knob or tubercle ; but by and by 

 it is a bulb, often separating spontaneously from the 

 parent plant and taking root in the soil. In some of 

 the alliaceous plants the caulinary bulb is very com-: 

 mon, and is produced at the origin and between the 

 spokes of their umbels. Among gardeners they are 

 known by the name of Cloves. 



Some plants produce a sort of bulb even in the 

 midst of their spike of flowers, which detaching 

 itself from the parent plant strikes root and forms 

 also a new individual. Such are Potygonum vivi- 



