(88) 



The bulbils of Lysimachia, however, are simply slender 

 stems in which elongation and differentiation has been 

 checked at an early stage, and the entire stele remains in an 

 embryonic condition. But little reserve food is accumulated. 

 The separation of the bulbil from the parent plant, and the 

 proper conditions of moisture and temperature act as stimu- 

 lants which incite a renewed development of all of the re- 

 gions of the organ. This results in the development of the 

 xylem, phloem and cortex in such manner as to fit the bulbil 

 for a life under the surface of the substratum, and for it to 

 become the subterranean axis of a new plant, which perishes 

 only by dying away slowly at the basal end after the manner 

 of such structures. The sheathing scale leaves only appear 

 to have attained full development during the stage of attach- 

 ment to the parent plant. This continued existence of the 

 bulbil of Lysimachia places it alone in a new category of 

 propagative bodies. 



The following statements may be made in conclusion : 



Propagation of Lysimachia terrestris is effected by the 

 branching and gradual death of the rhizomes, and by the 

 growth of bulbils formed in the axils of the aerial stems. 



The bulbils are branches of restricted development, of the 

 first and second order, which are formed under various con- 

 ditions unfavorable to the formation of seeds. Diffuse light 

 and low temperatures seem to be the principal inciting causes, 

 and these structures are formed in especial abundance in dry 

 seasons. 



The bulbils are free from transpiratory organs of any kind, 

 and resemble rhizomes in structure rather than aerial stems 

 on which they are borne. 



Detached bulbils are killed by exposure to a freezing 

 temperature in the open air, or by exposure to an atmos- 

 phere of a relative humidity of 30 to 40 per cent, for a day 

 or two, at a temperature of 18-22 C. 



The germination of the bulbil ensues without any appre- 

 ciable resting period, and is followed by the final stages of 

 the differentiation of the stele, which was checked during the 



