INTRODUCTORY LESSONS. 



a. Lupinus mi cran thus; 

 the first plumule leaf on 

 the left. 6. Lupinus ar- 

 boreus,asit appears when 

 grown In sand; the root- 

 hairs are ladened with 

 sand. c. Lupinus densi- 

 florus. d. The same, after 

 the cotyledons are fully 

 developed, and the plu- 

 mule has appeared. 



Lupines or- 

 dinarily grow as 

 represented in the 

 cut at a, but a com- 

 mon white-flower- 

 ed kind presents at the end of a month's 

 growth the queer appearance shown at d. At 

 first the sprouting seeds appear to be like 

 those of other lupines (see Fig. c), but when 

 the cotyledons open, they are seen to be united 

 by their broad bases. For two or three weeks the 

 cotyledons enlarge; not only becoming broader, but 

 thicker; yet we look in vain for a trace of the plu- 

 mule. Meanwhile a white pustule has been growing, 

 which finally bursts and discloses the partly grown 

 leaves of the missing bud, which has all this time 

 been hidden in the thick stem below the cotyledons! 

 "Now, the tough leathery skin of these cotyledons is 

 proof against the nightly frosts that prevail at this 

 season of the year (December), so they go on pre- 

 paring food from the air with which to feed the 

 tender plumule, until it also is strong enough to face c 

 Jack Frost. If you carefully examine these seeds in various 

 stages of their growth, you will learn that the plumule is at 

 the bottom of a short tube formed by the united petioles of 

 the cotyledons. Sometimes the plumule breaks out through 



